La Fortuna in Northern Costa Rica is home to one of the country’s most active volcanoes, Arenal. And where there is volcanic activity, there are hot springs. There is a whole industry built around hot springs, eco-tourism, and outdoor excursions here, and many hotels feature on-site hot springs and thermal pools. Here are the best hotels with hot springs in the region, from a mellow yoga colony under the volcano to the country's leading hot springs destination.