The hauntingly cryptlike Cave of the Seven Palaces (Cueva de los Siete Palacios in Spanish) is an ancient site and the strangely named home of Almuñecar's worthy archaeological museum,containing fascinating exhibits from local digs, including the oldest writing discovered anywhere on the Iberian Peninsula.
The troglodyte space now occupied by the museum consists of seven stone-built alcoves (named "the palaces" by locals) linked by a central vaulted passage. The exact nature and purpose of the dim and mysterious chamber’s origins divide opinion. The most accepted theory is that these vaults and alcoves were created by the first century Roman rulers of Almuñecar. Having rush out of building space on the crowded coastal hill occupied by the town, and Roman administrators had the "cave" constructed to support a wide platform projecting off the hillside,increasing usable space. It is supposed that the platform provided the foundation for the construction of a grand building, possibly a temple, or palace,or forum.
Despite the site being nearly certainly Roman in origin, evidence for human activity stretching back to the bronze age has been found in the cave, or which is perhaps unsurprising given Almuñecar's history as one of Europe's oldest inhabited settlements.
Whatever its original purpose,the space eventually became used as a cesspit, before being repurposed in the 1980s for a less smelly role as a home for some of the amazing artifacts discovered in the vicinity of the town, and including a beautiful stone vessel decorated with the earliest known writing discovered anywhere in Spain or Portugal.
Source: atlasobscura.com