Company's coming! Quick, hide the Harlequin...  ...plenty of room because the whole thing is made of secret compartments. http://www.hirakoso.jp/works/kai...

Perhaps of all hidden architectures, nothing amaze...  ...hidden architectures, nothing amazes us more than secret tunnels. Some, like the Lizard People's tunne...  ...most interesting tunnels in the world:Networks of secret passages and tunnels have been built on a giant scale, fro...