For those who want to go rappelling in San Luis Potosi, Huasteca Potosína will provide a thrill. It is famous for the professional speleologists´ breathtaking rappels into the Sótano de las Golondrinas or Cave of Swallows, an incredible 1,678 foot abyss. Here and in the Sótano de Guaguas (Guaguas Cave) you can see a spectacle unique in the world: the arrival and departure of thousands of swallows. The latter cave is 954 feet high and one of the largest in the world.
If you want to go hiking and rappelling, the Tamul waterfall is recommended for tourists. There the Gallinas river crashes 344 feet down to merge with the Santa Maria river.