Sótano de las Huahuas

Top choice in La Huasteca Potosina

This huge jungle-fringed sinkhole is home to tens of thousands of swifts as well as many green parrots, and at dawn and dusk they surge in or out of the cave in huge swirling, noisy flocks. It's much less touristy than Sótano de las Golondrinas, and so is in many ways the more appealing of the two to visit although it does require a little more effort to reach.

A favorite for rappelling enthusiasts, the chasm itself is around 478m deep and the cave mouth is around 60m across. To reach the cave from the car park you must walk 1km through remarkable jungle – but it’s worth it for its beautiful cedar and local tree and bird species.