At dawn above Aquismón, thousands of birds spiral up out of a vast hole in the ground. The Sótano de las Golondrinas, the Cave of Swallows, is a pit more than three hundred metres deep, one of the deepest open shafts in the world, and every morning swarms of swifts and parakeets rise from it in widening circles before flying off to feed. In the evening they return, diving straight down into the darkness like falling stones. It is one of the great natural spectacles of Mexico, and it happens just a short ride from this small Huasteca town.
Aquismón is a modest place of about two thousand people in the foothills of the Sierra Madre Oriental, the centre of a municipality inhabited largely by Teenek people, also known as Huastecs, who have their own language and traditions. The market and the plaza are a good place to see local life, and the food includes zacahuil and other Huasteca specialities. The surrounding landscape is a karst of limestone hills, caves, sinkholes and rivers, covered in tropical forest and sugar cane.
Beyond Golondrinas, the region is famous for its waterfalls and rivers. The Tamul waterfall, where the Gallinas River plunges more than a hundred metres into the canyon of the Santa María River, is reached by boat from nearby villages, a long paddle upstream through turquoise water between limestone walls. Other cascades and swimming holes are scattered throughout the area, and the clear blue rivers of the Huasteca Potosina are a delight on a hot day.
For riders, the roads around Aquismón are narrow, winding and steep, especially the road up to Golondrinas, which climbs in tight bends through the forest. Topes, animals and pedestrians are common, and the surfaces vary. Aquismón has limited fuel and basic food and lodging, so plan to fill up in Ciudad Valles or Axtla de Terrazas, the nearest larger towns. The climate is hot and humid, with heavy rains from June to October, which can make the rivers muddy and the roads slippery. The dry season is the best time to visit, when the rivers are blue and the roads are clear. Get to the cave before sunrise to see the birds leave.