Now called "Pirates Lair on Tom Sawyer Island," Disneyland's put a Pirate overlay on the classic playground for kids, where folks can run around and blow off steam built up from a morning of waiting in queues elsewhere in the park.
The biggest change is in the cave, which now features more detail, as well as a pirate audio-animatronic. Spend a few moments with him to see the full effect.
Other highlights include a walk-through treehouse, shipwreck play area, a barrel bridge, a suspension bridge and plenty of trails to explore.
Note that the only way on or off of Tom Sawyer Island is by raft, and you can face a few minutes' wait to get back on busy days.