Whole Cake Island is a New World island under the control of Big Mom, one of the Yonko. It is her crew's base of operations and the central island in Big Mom's 35-island archipelago known as Totto Land.
In addition to other minor islands in the Totto Land archipelago, Whole Cake Island is the primary setting of the Whole Cake Island Arc.
Layout and Architecture
The island is quite large, and until about 62 years ago, it was a regular island with several round hills. It was renamed to "Whole Cake Island" due to Charlotte Linlin and Streusen working to fulfill the former's dream, which was inherited from Carmel, and its new resemblance to a gathering of frosted cakes are due to the enormous cake buildings constructed there. Due to the buildings' enormous size, visitors tend to be awed at the first sight of the island. Atop the largest central building, the Whole Cake Chateau, there are massive poles shaped like candles, making it look like a birthday cake (being even depicted as lit, although it is unknown if their "flames" are real and the anime implies that they are trees). Most buildings appear to be covered in what looks like icing. The interiors of buildings in general look as if they are partly made of icing.
At least the island's southwestern coast is covered in a kind of hardened whipped cream, namely meringue.
Cities and Locations
Sweet City (スイートシティ Suīto Shiti?) is the capital of Whole Cake Island, and, by extension, of all Totto Land.  The city is situated northwestern to Whole Cake Chateau, roughly in the center of the island. Its structures and buildings are made of edible substances, such as candy or biscuits furnished by the Minister of Biscuits, with some of the buildings being living. Some of the them also bear "BM" or "BIG MOM", as an obvious reference to the island's queen. A juice river, seemingly connected to the sea or to Lake Aprico, runs through the town. Sweet City is seemingly surrounded by living hills, and a pathway links the Whole Cake Chateau to Lake Aprico. The citizens of the city appear to be quite diversified, as in all Totto Land. Some balloons covered with frosting can always be seen floating over the town, regardless of the weather.
However, some of the town was destroyed when Big Mom started eating it during one of her cravings; and when Charlotte Cracker was sent flying and defeated by Monkey D. Luffy, the city was put in a lockdown. Following the collapse of the chateau, the city was covered in cream and pieces of sponge cake.
The Seducing Woods
The Seducing Woods (誘惑の森 Yūwaku no Mori?) are situated in-between Whole Cake Island's southwestern coast and the outskirts of Sweet City. They were what the Sanji Retrieval Team visited first on the island after disembarking. Consistent with the island's theme, the forest is quite bizarre, being largely edible and full of homies, like trees, lollipops, cakes, and flowers, which can be seen happily talking and singing with each other. More specifically, the forest includes a river of melon juice running through it, a waterfall of apple juice and Brûlée's house next to it. A talking crocodile seems to inhabit the river, his role being to destroy a certain donut bridge leading to the coast. Pound also used to be buried there, until Charlotte Cracker came to pull him out of the ground. The forest's master was Kingbaum, the largest tree homie. In the anime, it was shown that the entire forest was brought to life by Charlotte Linlin's soul.
Contrary to its seemingly merry atmosphere at first glance, the forest has a strong sense of maliciousness, as there are skeletons of past wanderers laying around, and the trees and other homies constantly move around to block off exit routes and evermore shift the forest's very layout to confuse their visitors, regarding it as a "Game of Death", joyfully singing about how those visitors' brutal deaths might look like. In fact, the Homies, led by Baum, will not let go of unauthorized visitors relatively regardless of how strong they are. There is also a strong interference with magnetic fields to prevent visitors from finding a way out via Log Poses (seemingly due to strange clocks secured on some tree homies, whose clock hands spin uncontrollably).
Brûlée's house (ブリュレの家 Buryure no Ie?) is situated in the Seducing Woods, and the Mirro-World, with a large mirror in its middle, acting as a sort of bridge between the two worlds. On the Seducing Woods side, it is next to an apple juice waterfall. It consists of a watermill activated by the aforementioned waterfall, biscuit-made walls and a large roof, on top of which is a black cat figure, fitting Brûlée's witch theme. Inside, its walls are covered of mirrors. In its center, a large cooking pot is used by Brûlée to boil her captives.
Whole Cake Chateau
Whole Cake Chateau (ホールケーキ城 (シャトー) Hōru Kēki Shatō?) was the three-layered massive castle of Big Mom, and the largest cake building found in Sweet City. It had a total of ten floors,  and dwarfed essentially all the other buildings and landmarks of the island (actually being larger than Sweet City as a whole). It was situated roughly centrally on the island, being surrounded by Sweet City.
Lake Aprico (アプリコッ湖 Apurikokko?) is a large lake right behind (eastern in the anime) Whole Cake Chateau, which runs into the ocean. Right at the entrance to its port are two Tartes, and only Big Mom's associate crews (and those that are in the process of becoming so) are granted access to the port. Lake Aprico is the current main location of the ocean-going Germa Kingdom. Its name suggests that it may be composed of apricot juice.
Caesar Clown's Replica Laboratory
A replica of Caesar's Punk Hazard research facility on Whole Cake Island. Having acquired the blueprints, Big Mom had her first son, Charlotte Perospero, recreate the high-tech laboratory with pure candy, and then reinforce the entire structure with steel to prevent hazards and risks. It is located somewhere around Whole Cake Chateau.
While the building resembles Caesar's original laboratory and contains all the necessary equipment, certain towers and walls are labeled with "WCI", "WHOLE CAKE ISLAND", and "SWEET" instead of "PH-006" and other like codes.
Caesar was forced to work there to finish the gigantification drug he was commissioned by Big Mom to produce (but which he believes is impossible), but managed to strike a deal with Capone Bege for his release in exchange for his help in the assassination plan against Big Mom.
The Northeastern Coast of Whole Cake Island stands out in that, according to Capone Bege, it is the perfect place to "make a body disappear". This is due to a large group of extremely wild and ferocious, dotted sharks swimming in the sea around the shore, which will prey upon any so unfortunate to fall in their waters until not even a hair of them remains.
Fire Tank Pirates Hideout
The Fire Tank Pirates Hideout (ファイアタンク海賊団 アジト Faia Tanku Kaizokudan Ajito?) is a large dark cake building located in the northwest region of Whole Cake Island. It is where Capone Bege and his crew met to discuss their plans to turn against the Big Mom Pirates and take down Big Mom herself. It is also where they conduct meetings with potentials allies. With the crew defecting from the Big Mom Pirates after the failed assassination attempt, they have abandoned the base and the island.
- The Hideout have an unseen men's bathroom where Chopper took a bath.
- There is a Women's Bathroom (女風呂 Onna Buro?), where Nami and Carrot took a bath.
- There is a kitchen where Luffy and Brook drank milk.
- There is a large meeting room where the Fire Tank Pirates and the Sanji Retrieval Team talked about and formed their alliance before discussing their plan to assassinate Big Mom.
- In the anime, there are at least two wardrobes, one for men and the other for women.
Whole Cake Island is populated primarily by Big Mom's crew and allies, which include members of races from all across the world (except giants), even talking animals, and most of her over 80 children, as well as her grandchildren. At least one of her ex-husbands also resides on the island.
In addition, an extremely wide assortment of anthropomorphic singing animals and objects (the latter including primarily food) live on the island via the powers of the Soru Soru no Mi . All those seem to have a habit of repeating their noun name by way of singing or saying it in a melodic fashion; even living objects with a specific name use the noun and not their actual name; however, they are not limited just to saying their names and are capable of rational thought. Anthropomorphic fragments of Linlin's soul known as "incarnations" also exist freely on the island, collecting souls and performing other tasks for their owner.
61 years before the start of the series, the island was largely uninhabited, containing natural fields, hills, and forests. Streusen resided here, and Mother Carmel moved the Sheep's House here after one of her wards, Charlotte Linlin, was exiled from Elbaf. However, Carmel and the Sheep's House children disappeared by Linlin's own hand, and Streusen approached Linlin. The two banded together, and aimed to make the island into Linlin's dream paradise. As Linlin grew in power, this became a reality. Much of the island's nature was transformed into food, and Big Mom gave life to many of the objects and environment around the island with the power of the Soru Soru no Mi.
Fish-Man Island Arc
Big Mom, while preparing for a Tea Party, received a report from Pekoms and Tamago that Fish-Man Island had failed to provide its requisite amount of sweets for her. However, she then conversed with Monkey D. Luffy, who ate the sweets, and decided to transfer her grudge to him instead.
Whole Cake Island Arc
Three days before the upcoming wedding between Charlotte Pudding and Sanji, Big Mom entered one of her food cravings, laying waste to Sweet City as she searched for croquembouche. Jinbe managed to get her some croquembouche, and talked with Big Mom about him leaving her crew. While the city was undergoing damage control, she agreed as long as he spun a roulette wheel to lose something in return. Knowing that all the options would lead to his death, Jinbe backed out of the deal, and this was reported in the news the next day.
That day, the Fire Tank Pirates kidnapped Pekoms from Cacao Island and brought him to their base to recruit him in their plan to assassinate Big Mom. Pekoms refused, causing Bege to shoot him into the sea to prevent him from talking. Pekoms was rescued by the Sun Pirates, but they had to leave him tied up on the shore after Jinbe learned about the assassination plot. Meanwhile, Big Mom forced Caesar to continue working on his gigantification experiments in a new lab she had Charlotte Perospero construct, giving him two weeks to complete it before she executed him.
Meanwhile, the Sanji Retrieval Team arrived at Whole Cake Island, and Big Mom had Charlotte Brûlée and the homies in the Seducing Woods trap and attack them. Later, she sent Sweet Commander Charlotte Cracker to ensure they would be taken out, and Cracker engaged Luffy in battle. After an 11-hour battle, Luffy managed to defeat Cracker, sending him flying into Sweet City, while Nami had subdued all the Seducing Woods homies with Big Mom's Vivre Card. Cracker's defeat caused Sweet City to be put into a state of lockdown, and an army was raised to take out the Straw Hats. As this happened, the Vinsmoke Family headed into Sweet City to meet with Big Mom, and they ran into Luffy and Nami in the outskirts of Sweet City. There, Sanji feigned allegiance to his family and defeated Luffy, leaving him outside Sweet City as Big Mom's army marched there. After a long fight, the army defeated Luffy and Nami and captured them.
Luffy and Nami were imprisoned inside a book in the Prisoner Library, while the Vinsmoke Family met with Big Mom and Pudding. Sanji agreed to marry Pudding as long as Big Mom freed Luffy and Nami; Big Mom agreed to this, but never intended to honor it. Meanwhile, Brook and Pedro infiltrated the Whole Cake Chateau as they sought to steal Big Mom's Poneglyphs. Pedro fought Big Mom's guards in the Chateau as a distraction before confronting Tamago in the courtyard, while Brook slipped into the Room of Treasure and transcribed the Poneglyphs. Big Mom discovered Brook's presence and attacked him, eventually defeating him, but Brook had managed to get copies of the Poneglyphs. Meanwhile, Pedro ended his battle with Tamago by setting off a large number of bombs in his jacket.
Chopper and Carrot had been captured into Brûlée's Mirro-World, and after being chased and captured by Brûlée, they unleashed a plan to take out Brûlée and her henchmen. The plan succeeded, and they traveled through Mirro-World with Brûlée and Diesel as their prisoner escorts. They searched for their comrades, and found Pedro, bringing him in as he set off the explosion. Meanwhile, Jinbe broke into the Whole Cake Chateau and ambushed Opera at the Prisoner Library, freeing Luffy and Nami. Luffy went on ahead to warn Sanji, while Nami and Jinbe fought hordes of Big Mom Pirates until Chopper and Carrot brought them into the Mirro-World. Big Mom used Brook as a plaything and slept with him, and after a grueling effort the team managed to retrieve Brook. Meanwhile, Sanji discovered that the Big Mom Pirates intended to massacre his family at the wedding, and after much convincing eventually went back to Luffy.
That night, while the citizens of Whole Cake Island prepared for the wedding, the Straw Hats met with the Fire Tank Pirates to form an alliance to assassinate Big Mom and rescue the Vinsmoke Family. In the morning, the tea party and wedding ceremony then started on top of the Chateau, and before the Big Mom Pirates could assassinate the Vinsmokes, Luffy burst out of the Wedding Cake and invaded the venue. During the chaos that followed, Brook shattered Big Mom's portrait of Mother Carmel, causing her to have a crisis and weakening her. However, Big Mom foiled the Fire Tanks' assassination attempt by screaming, and the Big Mom Pirates lay siege to the Straw Hat-Fire Tank alliance. Even when the Vinsmoke Family joined their side and they tried a quick escape, the alliance was routed by Big Mom and her crew. However, the Tamatebako suddenly fell off the Chateau as some of her wedding guests scuffled over it, causing a massive explosion at its base that caused the entire structure to topple over. Streusen turned the venue into soft cake, saving everyone from the fall, and the Big Mom Pirates prepared to go after the enemy alliance, who had flown away to the northwest part of the island.
The alliance parted ways, and the Sanji Retrieval Team ran into the Seducing Woods. As the Big Mom Pirates strategized, Big Mom started craving for wedding cake, causing her eating disorder to act up. She went on a rampage through Sweet City, and Perospero lied that the Straw Hats had a backup cake, causing Big Mom to go and pursue them through the Seducing Woods. The Big Mom Pirates split their forces to go after the alliance factions, and several of them joined Big Mom in her chase of the Straw Hats. However, Nami managed to use Big Mom's homie Zeus to strike the Big Mom Pirates with a massive lightning bolt, although that did not stop Big Mom. The Sanji Retrieval Team made it to the Thousand Sunny on the coast, and they fought the Big Mom Pirates that were stationed there. Perospero managed to trap the Sunny and a blockade was called in to shoot the ship down. However, Pedro severely injured Perospero in a suicidal explosion, freeing the Sunny, and the Straw Hats used Coup de Burst to fly over the blockade, escaping from Whole Cake Island.
While the majority of the Big Mom Pirates pursued the Straw Hat-Fire Tank alliance members, some stayed to coordinate their forces under Mont-d'Or's orders. When they learned that the territorial sea slugs went missing, Mont-d'Or was shocked, and he later added the Sun Pirates to their list of enemies. As reports of Luffy and Katakuri's fight in the Mirro-World came in, Stussy revealed to Mont-d'Or that the collapse of the chateau was caused by the Tamatebako they obtained from the Straw Hats.
As the time for the Straw Hats to rendezvous on Cacao Island drew near, Mont-d'Or bragged about the power of the Big Mom Pirates to Morgans, believing the Straw Hats had no chance of escape. As the Big Mom Pirates closed in on the Thousand Sunny, he ordered his crew to keep the Den Den Mushi active to stay informed. When the Vinsmokes arrived at Cacao Island to assist the Straw Hats, he learned about the true fate of Nusstorte's pursuit squad and tried to contact them, while Niwatori had his fears confirmed. When the news of Katakuri's defeat was revealed to the Big Mom Pirates, Mont-d'Or was extremely shocked.
As the situation at Cacao Island escalated, Mont-d'Or desperately asked for Perospero to report Big Mom's status. Afterwords, Mont-d'Or learned about Morgans and Stussy's departure and ordered his crew to capture them before Morgans could report the recent events. After Big Mom ate the cake, the news of her calming down spread across Totto Land, as the citizens celebrated. Despite their efforts, the Big Mom Pirates failed to prevent the Straw Hats' escape, which angered Mont-d'Or.
- Being the central part of the Big Mom Pirates territory in the New World, the island also share the crew fairy tale and fantasy fiction theme.
- The Seducing Woods design and disorientation properties are a reference to Tulgey Wood from Lewis Carroll's, most famous novel, Alice's Adventures in Wonderland.
- The scenery on Whole Cake Island is similar to sentient flowers from the garden mentioned in Carroll's sequel novel, Through the Looking-Glass, and What Alice Found There.
- A major influence appears to be the works of Walt Disney and the Silly Symphonies series of cartoons, in particular the 1932 cartoon Flowers and Trees (involving a forest of sentient plants) and 1935's The Cookie Carnival (involving a city made of sweets inhabited by candy people).