A shelter at the foot of the castle
The Algepsar Cave is an artificial cavity on the castle hill, within Onda's historic quarter. Its name comes from algeps, the gypsum traditionally extracted from cavities like this one. For generations it was just another part of the urban landscape next to the fortress, until the Civil War gave it a role that would mark its history.
In June 1938, Onda was on the front line of the bombing raids that hit the area. The population sought shelter at various points around town, and this cave, because of its location and structure, became one of those shelters. The cavity itself no longer meets the safety conditions needed for visits, so the museum project focused on fitting out the entrance tunnel to house a permanent exhibition.
The town council framed this space as a democratic memorial: a way to remember what happened in Onda during the Civil War so new generations know this chapter of local history.
The Espai de la Memòria
The space opened to the public in 2019, after the entrance was refurbished. The permanent exhibition opens with a short introduction to the Spanish Civil War, then moves on to recovered images of the 1938 bombings, photographs of the sheltering population and a brief period film. It closes with a memorial to Onda's war victims, and the chance to look into one of the cave's entrance mouths.
The Algepsar Cave's Espai de la Memòria is part of the Ruta de la Memòria (Memory Route), designed by the Valencian Federation of Municipalities and Provinces (FVMP), a network of democratic memory sites across the Valencian Community.
Where it is and how to get there
The cave is in Onda's historic quarter, at the foot of the castle hill, very close to the Prison Tower and the Plaça de l'Almudí. It's a short walk from the centre, following the road up towards the castle.
According to Onda Turisme, the cave is temporarily closed and there is no planned reopening date. Before heading over, check its status on the Onda Turisme opening hours page or call +34 964 60 28 55.