Tradition has it that it was built by rey alfonso i the catholic on february 21st 746 with excavations carried out before conversion work started on the building for the parador supporting the idea the present monastery was founded on the site and run by the order of san benito until the 1835 sale of church lands the monastery was declared a national monument in 1907 with a new wing added using matching building materials to match the original set on the green banks of the river sella t