Very original trekking in Castelvecchio Nature Reserve, a few kilometers from San Gimignano. Along this fascinating hike we will visit the magnificent ruins of this beautiful medieval hamlet, "The Old Castle". On the top of the hill you will see two towers and huge parts of defensive walls, the church, a water reservoir and many traces of buildings. The natural border of this incredible place are two ravines (a good defense in centuries of wars) hiding botanical rarities due to a special microclimate. Finally, you'll be thrilled and surprised by Botro ai Buchi, "The Holes Canyon" with some demanding passageways. Half a day will be enough to visit the castle and a small part of the defensive ravines. With the whole day you'll have a complete, gorgeous, demanding loop.