The Sharks' lair

In Finding Nemo, the sharks Bruce, Anchor, and Chum all appear to reside in a sunken battleship (resembling a World War II-era submarine) surrounded by various naval mines (described by Dory as "balloons"). After Bruce accidentally causes the mines to explode by ramming into one of  the shipwreck's torpedo bays where Marlin and Dory are hiding in, sending the torpedo flying out and hitting the mines, the explosion also caused the shipwreck to slide into the abyss only to be stopped by a nearby wall.