メンタナの天然記念物・トップ5

From here on, it's a hike for experts. There are no CAI flags (or at least I didn't see any), nor is the trail clearly marked. There are only a few stone cairns, but it's mostly a matter of feeling. The return time is much longer than indicated.

Danger!!! the path is not calculated well!!! attention!!!! only for experts!!!!

The nature reserve extends over about a thousand hectares between the Tiber Valley and the Cornicolani Mountains, in the Roman Sabina. The landscape is hilly, with pasture areas, crops and fragments of woods, remnants of the original forests. The area is known for its botanical value and for karst phenomena such as caves and sinkholes, including the Pozzo del Merro, one of the deepest in the world. The reserve also preserves historical evidence, from prehistory to the Middle Ages.

Strada Bianca connecting via della Cesarina and via di Casal Boccone. The first stretch is a dirt road up to the bridge that crosses the ring road; then continues on a beaten path between cultivated fields. It ends with an easy singletrack up to Via Casal Boccone skirting the Almaviva building.

The Pozzo del Merro is a karst sinkhole located in the countryside north of Rome, between the Cornicolani Mountains in Macchia del Barco and Macchia di Gattaceca, in the municipality of Sant'Angelo Romano. According to initial studies by the University of Tor Vergata, the cavity is 392 meters deep, which is the maximum limit the measurements have reached. The probes launched since its discovery have not reached bottom, and the studies continue. This sinkhole has always been known to the locals. In 1890 it appears in the description of a tourist itinerary that leads from Rome to Sant'Angelo Romano, and is described as "a kind of chasm, at the bottom of which extends a small lake and whose very steep sides are covered with trees". https://www.sotterraneidiroma.it/sites/pozzo-del-merro

More than a trail marker, this ancient beech tree is a timepiece! Perhaps this is why some of its protruding roots protect a small improvised nativity scene. The "troscia" indicates the puddle of water that you come across on the path just south of the beech tree.

You can still follow the path by bike, but you pass in front of inhabited houses

a nice walk