Hexagonal Bullring Monument · Almadén, Valle de Alcudia, Ciudad Real A bullring with a hexagonal plan, unique in the world, begun in 1752 and completed in 1765. Its outer perimeter houses 24 dwellings and the ring holds some 4,000 spectators; it was declared a Monumento Nacional (Spain's heritage designation in force until 1931) in 1979. Photo: Raimundo Pastor (CC BY-SA 3.0) What to see and do in Almadén