Four hundred religious monuments in Spain are in serious danger due to neglect, Hispania Nostra, a nonprofit that works to promote and conserve “cultural and national heritage” in Spain, said in a statement Thursday.

Hispania Nostra publishes a record of different monuments, buildings, and sites of archaeological importance around the country and the condition they’re in. The Red List, which is published on a rolling basis, notes which sites are in a state of serious disrepair; their most recent update notes that many religious monuments are fading away due to neglect and looting.

“Monasteries, hermitages, monasteries, churches and hospitals were abandoned, if not razed, vandalized and looted, and what used to be monuments that housed valuable libraries and works of sacred art, were reduced to a heap of rubble,” reads the statement.

“Many times, the stones and wooden beams of these convents were uprooted to build houses, fences or even bullrings, while the most valuable and elaborate ones (capitals, columns and even entire cloisters) were sold, sometimes to foreign buyers.”

Hispania Nostra pointed out sites like Sanctuary of the Virgin of Grace which was built in 1795 and is located in Teruel in eastern Spain. Only its walls and floors remain, but the imagery that once adorned it have all been erased by time, the organization said. Many of the sites on the list contain decorative elements such as frescoes and altar pieces that are being destroyed by humidity and lack of care.

The organization pointed to the Hermitage of San Jorge, near Cáceres, which contains a number of beautiful frescoes, as a site that must be attended to immediately, or its frescoes will be lost forever.