Cave Houses of Petrer Monument · Petrer, El Vinalopó Mitjà, Alicante The Casas-Cueva of Petrer, considered the town's typical monument par excellence, are dwellings excavated in the late 19th century inside the castle wall. Today they function as a museum that recreates their use as family homes, with a stable temperature of around 20 degrees all year round and a collection of everyday objects from the 19th and early 20th centuries showing how the families who lived in them used to live. Photo: Wikipedia / Wikimedia Commons (CC BY-SA) What to see and do in Petrer