Barranca de Metztitlan

East of Pachuca the highlands split open into the Barranca de Metztitlan - a biosphere reserve of nearly a thousand square kilometres where desert and water share one canyon system. The gorge walls and slopes grow one of Mexico's richest cactus communities: forests of viejitos - the white-haired old-man cactus that is the reserve's emblem - alongside giant barrels, candelabra and organ pipes, many species found nowhere else, blooming defiantly against red rock. On the canyon floor, the Venados river fans into fields of chile and corn before pooling in the Laguna de Metztitlan, a wetland of pelicans, herons, ducks and winter migrants that earns the reserve its Ramsar listing; fishermen pole flat boats between flooded willows. Above it all, the town of Metztitlan - "place of the moon" - climbs to its fortress monastery of Los Santos Reyes, a 16th-century Augustinian pile whose frescoed cloisters and terrace overlook the whole green-and-desert paradox. Few outsiders come, which for the canyon's herons and hermits suits fine.

What you actually see

• The old-man cacti - white-maned viejitos by the hillside thousand.
• The lagoon - pelicans and herons on a canyon-floor wetland.
• Los Santos Reyes monastery - frescoes and terrace views over the barranca.
• The farmed canyon floor - chile fields between desert walls.

When to go

November to April for dry roads and wintering waterbirds; cactus bloom scatters through spring. Mornings light the canyon walls and fill the lagoon with fishing boats.

Honest expectations

This is remote, service-light country - fuel up, carry cash and expect simple food. Roads into the canyon are winding and slow. A guide or boatman multiplies both birds and stories.

Nearby

The Huasteca's water country falls away eastward; Pachuca, Real del Monte and the Prismas lie back up the highland road.