Introduction to the Valley of the Dead: The Valley of the Dead (Valle de Los Caídos) is a Catholic cathedral and monument built by Franco. It is located on a hill 910 meters above sea level. The memorial tower is 150 meters high and is used to commemorate those who died in the Spanish Civil War. The construction of the Valley of the Dead took 18 years to complete, and the ribbon was cut in 1959. The building itself is a representative work of Spanish architecture in the 20th century.