The Drum Rockies are a chain of drum-shaped mountains on Drum Island. On the tallest mountain is Drum Castle, where Wapol used to live and Kureha took up residence after him.
According to Dr. Kureha, the peak plateau of the highest of the Drum Rockies lies more than a staggering 5000 m over sea level.
- ↑ 1.0 1.1
One Piece Manga and Anime — Vol. 15
Chapter 132 and Episode 79.
One Piece Anime — Episode 84,
Doctor Kureha expresses disbelief at Luffy's feat of climbing to her castle with his bare hands while carrying two people.