The Lost Coast trail is in the King Range wilderness in northern California. The trail runs along the coast and is literally underwater when the tide is high, so an interesting facet of this is that the cliff side precludes simply walking inland. People have drowned here, and the forest service is quick to emphasize the danger. They post tide tables at every trailhead in the reserve. Couple this with the extreme lack of water at altitude, it makes for an excellent wilderness experience.