San Salvador de Valdediós Monument · Villaviciosa, Gijón, Asturias Known as El Conventín, it was consecrated by seven bishops on 16 September 892, in the time of Alfonso III, although it is possible that only the side porch, added late to the temple, is owed to this king. It is the last great work of Asturian pre-Romanesque architecture, with three vaulted naves and remains of its original mural painting. It was connected to the neighbouring monastery of Santa María by a passage demolished in the mid-19th century. Declared a Monumento Histórico-Artístico (an earlier Spanish heritage protection category, predecessor of today's Bien de Interés Cultural) in 1931, it was restored by Luis Menéndez-Pidal y Álvarez in 1954 and 1970, and in 2011 a first phase of comprehensive rehabilitation was completed that consolidated the building and returned handmade Roman-style tiles to the roof; a second phase, focused on the interior and the mural paintings, remains pending. Photo: AdelosRM (CC BY-SA 3.0) What to see and do in Villaviciosa