Crawl down an abandoned mine shaft in the south of Spain and then descended further still via a narrow staircase and you’ll find yourself in a magical world: a cavern filled with human-sized, sparkling crystals. This is the Pulpí geode, the second-largest known geode in the world. The Pulpí geode sits 164 feet below Mina Rica, a silver mine on the coast of Almería that was abandoned in the 1960s. The natural wonder lying below the mine was discovered by geologists in 1999, and it took another 20 years before…
