This complex cave system with 19 galleries and a lengthy underground trail is close to town at the top end of Calle Independencia. Guides are required as there are no installations or signs here. Go with a qualified local guide who can offer helmets and headlamps. The walk to the cave is 1km. Those who are not too claustrophobic can squeeze into an inner chamber with a lake where you can swim. Reserve at least two hours for the excursion.
Locals have been working arduously to clean up this trail and remove an improvised trash dump from near the entrance, but it's still a work in progress, particularly before and near the entrance.