One of the most beautiful natural areas not only in the state of Hidalgo but in all of Mexico, Grutas Tolantongo is a true oasis where you can swim in multiple pools fed by thermal waters, relax in an impressive turquoise river, or even get on one of the four zip lines. Imagine yourself soaking in pools of naturally-heated water, cascading down the steep mountainside, the water flowing from one pool to another, with breathtaking views of the canyon below.