We found something very interesting completely by chance as we were walking home from a long hike in the castello the state-like municipalities in San Marino are called "castelli" of Aquaviva. The road we had walked on in the morning seemed too sunny for the late afternoon and so we decided to cut up and under this cliff face where it looked cooler. --- --- --- In the shade we spotted this long staircase. It scaled the rock in a series of sharp switchbacks and seemed to end at a small dark spot in the rock. We weren't too excited about it - it had been a long day of hiking and stairs weren't especially appealing. As we passed by though we saw a sign. The dark smudge up on the cliff it turns out is the cave of Saint Marinus. We had to go up.