Sotano de las Golondrinas, one of the largest pit caves in the world. Imagine a cave where vertically you could fit the Eiffel Tower, and at the bottom – three football fields.  What is more, thousands of birds live in its interior and perform a breathtaking ritual at sunrise and sunset.

Despite the name, the Cave (or the basement, if you insist on translating literally) doesn’t host swallows, but white-collared swifts and green parrots. Every morning, right before sunrise, these birds wake up and start circling around the walls of the cave. Observers at the rim of the sinkhole at first can only hear a loud whistle, then they can make out tiny little shapes. Thousands at a time, the birds circle round and round, in an orderly, well-organized fashion, the whispering becoming louder. The effect is truly hypnotic! Once a minute around 50 take off and fly outside at a dizzying speed, in a suddenly disorganized and erratic way – to confuse the hawks sitting on nearby peaks, waiting for the right moment to attack. They are out all day, flying towards the Gulf Coast in search of food. In the evening they fly back forming spirals above the sinkhole, in groups of hundreds, only to precipitate down to the abyss – with folded wings, making a loud whistling sound while they return to their nests for the night. This “show”, as the locals refer to it, repeats almost every day – on very cold or rainy days the birds don’t feel like sticking their beaks out.

The cave was initially interesting only for the scientists, but in recent years it attracts speleologists, daredevils and tourists, drawn to this natural wonder. Many come to try extreme rappelling and the descent exceeds any expectations – Sotano is the Mount Everest of rappel, certainly not the right place for first-timers! When you do decide to rappel down its 370 meters of free fall, it seems at first that you go down too slow, until you suddenly reach the bottom. Metal parts of the rappelling equipment heat up during the descent and you have to cool them down by sprinkling water on it – otherwise the heated metal can melt the rope. It’s not great idea to stop midway either – you can cause overload on the equipment. Once at the bottom, you might suddenly think of the James Cameron movie “Sanctum”….it’s not exactly pleasant, sharing this space with snakes and scorpions, the air smelling of fungi, but you definitely feel the ambience of a different planet! Now the hard part comes – getting back on the surface. Depending on your skills and fitness level it may take you an hour or two but in the end you’ll know it was well worth the effort! The experience in unforgettable and the adrenaline boost will keep you going for a long time!

For less experienced rappellers and first-timers, there’s dozens of other caves around the Sotano where you can try this sport. Among our favorites is Sotano de la Jeringa (the Syringe Vault), a 50-meter-long tube which looks like the official entrance to the inferno, as you can’t see deeper than 5 meters down. On the bottom you might have to share the confined space with a few spiders but it’s surprisingly not dreadful at all, especially when looking up, towards the tiny speck of light being the exit.

Apart from being a natural wonder and a haven for extreme sports fans, Sotano has another advantage: its location. Huasteca Potosina is one of the most beautiful and all-green corners of Mexico. Your options are innumerable: rafting or a canoe ride on one of the nearby rivers, swimming and chilling by the waterfall or a visit in one of the archeological sites which used to be the center of the Huastec imperium – one of the least known Mesoamerican civilizations. But wait, there’s more: it’s still unexplored by tourists so, apart from the Easter season, you’re likely to admire these paradise spots in natural and serene environment!