Prismas Basalticos

The Barranca de Santa Maria Regla is walled with geometry: columns of basalt, five- and six-sided, up to forty metres tall and packed like organ pipes, formed as ancient lava cooled slowly and cracked into prisms. Four streams of the San Antonio dam pour over the rim between them, and the ensemble - green pool below, geometric walls, waterfalls threading the joints - has been a celebrated wonder since Alexander von Humboldt sketched it in 1803 and pronounced it among the world's marvels. A hanging bridge crosses the gorge at rim level for the full vertiginous view; stairways descend past the columns to the pool, where the scale becomes physical - each column about as thick as a tree trunk. The surrounding park, on the lands of the old Santa Maria Regla silver hacienda, adds trout restaurants, cabins, boats and zip lines in the cheerful Hidalgo country-park manner, and the hacienda itself - arcades and smelting arches - anchors the far end. Rainy-season months send all four falls thundering; the dry season thins them to veils but leaves the columns in sharper light.

What you actually see

• The basalt prisms - forty-metre geometric columns walling the gorge.
• The four falls - dam streams pouring between the pipes.
• The hanging bridge - the rim crossing above the pool.
• Hacienda Santa Maria Regla - the silver estate at the canyon head.

When to go

June to October for maximum water; November to April trades flow for clear skies and firm trails. Early weekday visits beat the tour buses to the bridge.

Honest expectations

The falls are dam-fed - volume varies with releases and season, occasionally to a trickle. Stairs into the gorge are steep and spray-slick. Weekends run to full family-park bustle.

Nearby

Huasca de Ocampo's pueblo magico plaza, the ex-hacienda of San Miguel Regla and Real del Monte's mining lanes are all within half an hour.