Under the village of Lapas two kilometres from Torres Novas is a spectacular labyrinth of tunnels hewn from the soft tufa rock.

Just who dug these tunnels and for what purpose remains a bit of an enigma; theories vary from Neolithic tribes for shelter, to Christians seeking refuge during Roman times or the Moors for defence and storage.

They may also have just been a medieval mine for building material, as most of the houses in Lapas are built from the same tufa stone.

Either way, you can come and explore; all you have to do is knock on the door of the caretaker who will let you in.