A Real Gruyere Cheese
I recommend the visit of the tunnels of Alfonso VIII, named after the street at the entrance, just in front of the Casa del Corregidor and the Palacio de los Clemente Aróstegui.
They form a labyrinth full of passages, galleries, caves of various kilometers long and which have been dug by the people of Cuenca throughout the centuries in the underground part of the city, turning it into a real gruyere cheese. They were built with different purposes: from caves to preserve wine and food, to communication routes between buildings, tunnels for escaping and they were also used as improvised anti aircraft shelters during the civil war of 1936-1939.