Barra Honda National Park, Costa Rica

Mushroom Hall is named for the shape of its flat formations which resemble the outlines of mushrooms. You can also let your mind run wild in the Hall of the Caverns, a place of spiraling and twisting formations, including one that resembles a lion&s head. Tap the rock formations to hear them chime or listen to the bats flutter throughout the interior. At this national park it is nearly impossible not to stand in awe of such an incredible geological wonder.

Remarkably, the park is home to a number of rare species, found only at Barra Honda. Because of its unique subterranean environment, blind salamanders and endemic fish species have evolved as a result of the complete darkness far below ground.

The park is also superb for exploring above ground. Anybody can hike the numerous trails that are found on the 5,670 acre (2,295 ha) plot, a great way to encounter the rich animal life found throughout the scrubby landscape. Here you will find everything from monkeys to scarlet macaws as well as a host of other exotic species that inhabit the park.

If you do decide to explore some of the deeper caves that the park has to offer, it will require the proper mountaineering equipment. Groups are required to phone the National Parks office in advance for approval to descend into the caves.

The park's ranger station is accessible from the Tempisque ferry by driving north through the community of Santa Ana. The road is best traversed in a four-wheel drive vehicle, as the going can be rough. The eastern portion of the park can be accessed via the rural town of Quebrada Honda.