La Reforma, Volcanic caldera in Baja California Sur, Mexico

La Reforma is a Plio-Pleistocene caldera in Mulegé, Baja California Sur, with a diameter of 10 km and a rim 100 to 500 m high. Its semicircular structure wraps around Cabo Virgenes, and a resurgent dome of welded tuff rises 700 m above the caldera margin to 1,200 m above sea level.

This caldera formed millions of years ago through volcanic activity in the Gulf of California region. The geological processes that shaped it are connected to the broader development of the Baja California peninsula.

The caldera lies in Mulegé municipality, 20 km north of Santa Rosalía, the copper-mining town whose marine Pliocene sediments hold the region's copper and manganese ores. The rim encloses Cabo Virgenes, a semicircular rock headland reaching the Gulf of California at La Reforma in the northwest and Punta Las Cuevas in the southeast.

La Reforma lies in Mulegé municipality, 20 km north of Santa Rosalía, just south of the Baja California–Baja California Sur border. The rim stands 100 to 500 m high and the resurgent dome inside rises 700 m above the caldera margin, reaching 1,200 m; the semicircular rim runs from La Reforma on the Gulf of California northwest to Punta Las Cuevas southeast. Approach from the Santa Rosalía side.

The resurgent dome inside the caldera is made of welded tuff and rises 700 metres above the caldera rim, reaching 1,200 metres above sea level. Some geologists instead read La Reforma as an eroded dome or a set of tectonic blocks, so its origin is still debated.