The largest cave system in Cuba and the second largest in the Americas: over 46 km of surveyed passage in galleries stacked on seven or eight levels, depending on whose survey you read, draining the 400 metre Quemado range. About a kilometre of it is set up for visitors and you go in with a guide and a lamp. Sources disagree on the level count and the exact length, which is normal for a cave still being mapped. El Moncada, about 20 km west of Viñales, Pinar del Río.
Other places on the map within a couple of hours.