"Powered by the Rincón de la Vieja volcanic system, this combined adventure-and-spa facility pairs thermal pools with high-energy activities such as zip-lining, horseback riding, and a giant waterslide. The site features man-made pools filled with volcanic thermal water and offers mud baths and mineral treatments for guests seeking restorative or novelty spa experiences after outdoor adventures." - Ashley Harrell Ashley Harrell Ashley Harrell is a Northern California-based journalist who writes about the sea, wildlife, travel, and more. As a Lonely Planet writer, she's co-authored 48 guidebooks in 15 countries and serves as an editor at SFGate. Travel + Leisure Editorial Guidelines