Grotta dell’Arco

Grotta dell’Arco di Bellegra

Useful Information

Location:	Località Le Cese, 00030 Bellegra RM. A1 Rome-Naples motorway exit Colleferro, left on SP21 8.2 km, in Paliano tunr left on Via Mola Del Casale 2.8 km, turn right on SR155 4km, left on SP198/SP26c/SP110a. E80 Rome-Aquila motorway, exit Castel Madama, SP33a 11 km, left on SP47a 2.7 km, right towards Gerano 2.5 km, left on SP48a/SP27c/SP63a/SP62a 10.5 km, turn left to Vaccarecce, after the village right. (41.8913514, 13.0479568)
Open:	Online booking mandatory. [2024]
Fee:	Adults EUR 10, Children (6-12) EUR 8, Children (0-5) free, Disabled free. Percorso Speleo Turistico: Adults EUR 23, Children (6-12) EUR 18. Percorso Speleo Avanzato: Adults EUR 40, Children (6-12) EUR 35. [2024]
Classification:	Karst Cave
Light:	Incandescent
Dimension:	L=1,000 m, VR=23 m, A=425 m asl, T=16 °C.
Guided tours:	L=600 m, D=1 h. Percorso Speleo Turistico: L=1.4 km, D=2 h. Percorso Speleo Avanzato: L=2.3 km, D=3 h.
Photography:	allowed
Accessibility:	yes
Bibliography:
Address:	Grotta dell’Arco, Località Le Cese, 00030 Bellegra RM, Tel: +39-0
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

19-JUN-1925	speleologic exploration by the Circolo Speleologico Romano (CSR).
04-APR-1996	speleologic exploration by the Gruppo Speleologico Grottaferrata (GSG).
1999	two groups of cave paintings were discovered.
2017	managed by Sotterranei di Roma.

Description

The Grotta dell’Arco (Arch Cave) is often called Grotta dell'Arco di Bellegra (Arch Cave of Bellegra). Arch Cave is one of those names which exist multiple times, its quite generic, and so they add the location to make it unique. The cave itself has no arch, it was named afte a natural bridge which is further down the valley.

The valley at the cave entrance is named Valle del Pantano (Pantano Valley). Until 1911 was filled with a lake named Pantano di Roiate. This lake was fed by the cave river emerging from the cave during the wet season. It was filled by the winter rains, and lowered during summer. It was artificially drained in 1911 to recover land for cultivation. The locals feared that the lake area would become State Property as per Royal Decree. This had already happened at Lake Gabi and Lake Fucino.

The cave was in the epiphreatic zone, it was sometimes flooded, but most of the year there was no cave river. The cave was first explored by the Circolo Speleologico Romano (CSR) in 1925. But this was not its discovery, it was actually known for a long time. Since the 19th century the water in the cave was used to grind grain. There was a waterwheel and a grindstone named Mola, which were driven by the cave river, although it flowed only during winter. To optimize this, a dam was built and as a result the entire cave was flooded. But in 1955 electricity arrived in the area, and the mill was not profitable any more, both the mill and the dam were decommissioned.

The cave was frequented by cavers after the dam was removed and there were several discoveries, like the bones of Cave Bears (Ursus spelaeus). And nice speleothems. In the 1990s the cave was developed as a show cave, and the trail allowed the view on the ceiling. Before the cavers were concentrated to walk in the trail and were thus not looking up. So the visitors were quite astonished by two groups of cave paintings on the walls, one in red and one in black. They are though to be from the Copper Age, the late Neolithtic, or probably from the earl Iron Age. As the cave most likely had a river when the paintings were created, they ore thought to be linked to a water cult. The paintings are about 3 metres above the current floor level, which is above the level of the cave river during floods, otherwise the paintings would have been destroyed. It seems the floor was higher when they were painted, remains of former higher floor levels can be seen on the walls. They were eroded by the cave river.

For some reason it is managed by the Sotterranei di Roma, who are actually not cavers but urban explorers, and they organize trips into about 30 artificial underground places in the city. In this cave they offer three different tours, the regular tourist tour, a Percorso Speleo Turistico tour and the Percorso Speleo Avanzato (Advanced Speleological Route). The regular tour is on an elevated walkway, and the cave is equipped with electric light. The tour is without any barriers and wheelchair accessible, which is quite exceptional. The Percorso Speleo Turistico is what we normally call semi-wild cave, a horizontal passage without difficulties, easy to visit, but without trails or light. Visitors are equpped with gum boots, helmet, and headlamp. The Advanced Speleological Route requires crawling and a little climbing. Participants get an overall, in addition to the basic equipment. The tour ends at the sump.