Luca Andreoni
Cisterns of the Pianello,
Michele de Giohanino [1476-78]

Tunnels along the Rimini-San Marino railroad,
Filippo Tajani [1928-32]
Moreno Gentili
Rock quarries, XIX century
Alessandro Scotti
Ancient walkways to climb the Mountain, from the Stradone to the tip of the wall towards the sea (Pelacchi, 1776),
Gino Zani [1925-41]