Venado Caves Underground Experience from La Fortuna. Slip beneath the ground on a 4-hour tour through the Venado caves from La Fortuna, and follow underground trails into a series of remarkable grottoes and chambers. Gear up and follow your flashlight along an ancient seabed as you explore the caves with your guide. Get wet and get dirty on your way to fantastic rock formations and bristling stalactites and stalagmites, visit a bat colony that thrives in the cool, dark cave system, then return to the surface to enjoy a snack of tropical fruits. Book and Save 15%! Venado Caves Underground Experience from La Fortuna.