The Sea Forest (海の森, Umi no Mori?) is a place in the north-east of Fishman Island known as Ship Graveyard.

It has a lot coral growing around it, more than normal due to the light emitted by the Sunlight Tree Eve. It is populated by all kinds of sea fauna, including schools of fish and large whales. There are also several shipwrecks there because the sunken ships are dragged there by the ocean currents, here the epithet "Ship Graveyard". The Thousand Sunny was swept here when the Straw Hats entered Fishman Island. According to Robin there is a possibility that a Poneglyph is hidden there.

http://images.wikia.com/onepiece/images/2/21/Sea_Forest.png