Trofeo Proloco Città di Anguillara Sabazia - 5km

Under regional environmental protection, Lake Bracciano remains closed to private motorboats, preserving a calm freshwater surface suited for long-distance endurance. The Trofeo Proloco Città di Anguillara Sabazia - 5km is an open water swimming race held in the waters of Lake Bracciano at Anguillara Sabazia, in the Lazio region of central Italy. The course is set right off the scenic cape where the historical settlement of Anguillara Sabazia extends into the lake basin. Swimmers gather along the shore to tackle a continuous 5,000 meters organized by the Pro Loco Anguillara Sabazia. Slicing through the freshwater, competitors navigate by sighting landmarks along the shoreline and turning around the course markers in sequence. Within competitive Italian open water swimming, the event holds an official spot on the national Grand Prix Fondo Agonisti circuit, attracting distance specialists eager to test their pace over the classic five-kilometer mark.

Lake Bracciano: the Sabatino caldera and its motor-free basin

The expanse of water hosting the race occupies a volcano-tectonic depression that began forming roughly 3.7 million years ago. It is part of the Monti Sabatini area, where intense volcanic episodes developed between 600,000 and 100,000 years ago. Over time, the activity of the extinct Sabatino volcano shaped a wide crater surrounded by green, wooded hills. Across this volcanic complex, a sedimentary base lies buried beneath a layer of volcanic ash and rocks about 200 meters thick. Out on the course, the lake bed falls away to reach a maximum depth of approximately 160 meters. On the southeastern shore, the Arrone river forms Lake Bracciano's only emissary, draining its surface runoff and carrying it on a journey down to the Tyrrhenian Sea. About eleven kilometres away, near the Valle di Baccano, lies the site of the ancient Mansio ad Vacanas, situated beside an ancient volcanic lake that was drained in later eras.

La Marmotta: prehistoric canoes beneath the lake floor

About five kilometres from the race area, roughly 300 meters from the lake edge at a depth between 7.5 and 11 meters, sits the underwater site of La Marmotta. This submerged settlement is the oldest Neolithic lake dwelling discovered in Europe, having been inhabited continuously for at least five centuries between 5700 and 5200 B.C. More than 3,400 wooden posts that once supported prehistoric lakeside dwellings have been excavated from the lake floor. Excavations at La Marmotta uncovered five dugout canoes dating back 7,500 to 7,000 years, carved from oak, alder, poplar, and beech, with lengths spanning between 5.4 and 10.43 meters. In July 2005, archaeologists recovered a 9.50-meter-long canoe carved from a single oak trunk at a depth of 12 meters.

Hunters in the village also relied on archery, evidenced by nineteen wooden bows discovered during underwater investigations. Along other stretches of the perimeter, submerged findings at Vicarello, Sposetta, and Vigna Grande reveal additional protohistoric settlements preserved beneath the lakebed. Anguillara Sabazia takes its name from an ancient Roman villa known as Angularia and from the Anguillara family, who held the fiefdom until 1488. Near the lake, the Roman villa of Mura di Santo Stefano stands with structural remains dating from the end of the 2nd century AD. On the western side of the basin, about six kilometres away, lay the ancient settlement of Forum Clodii, with a branch of the road continuing along the northern shore towards Trevignano Romano.

Anguillara's old town on its promontory above the lake

The old town of Anguillara Sabazia stands on the promontory where a large Roman residential and productive complex, identified by archaeologists as Angularium, once stood. The Roman villa at Anguillara had a lake landing stage, probably with a lighthouse tower, and part of the harbour structures was submerged around the middle of the 1st century AD as the lake level rose. The medieval village of Anguillara grew on the same promontory, in a position dominating the lake and the mouth of the Arrone. During the rule of the Orsini family, the fortifications of Anguillara were extended and the baronial palace, now the town hall, was renewed. The defensive complex, with the Castello gate, the round tower, the walls and the bastions, took on much of its present appearance between the 15th and 16th centuries. The Collegiata di Santa Maria Assunta stands at the highest point of the promontory that carries the old town of Anguillara.

Lake Martignano and the regional wetlands

Just three kilometres east of Anguillara Sabazia lies Lake Martignano, a companion volcanic body of water nestled inside an extinct crater known as a maar. Both Lake Bracciano and Lake Martignano are protected within a regional park. In Roman times, Martignano was called Alsietinus Lacus and belonged to southern Etruria. Emperor Augustus drew its water to Rome through the Aqua Alsietina aqueduct to supply his naumachia, a basin dedicated to mock naval combats. Traces of this Roman conduit were potentially noted in 1720, and an inscription documenting the Aqua Alsietina came to light in the area in 1887. This regional reserve forms the second most important wetland in Lazio for wintering aquatic birds.

Lake Martignano regularly shelters significant numbers of the rare red-crested pochard duck. Around Martignano, visitors find a quiet setting featuring a lawn beach, cafes, restaurants, and walking tracks looping through the lakeside greenery. Less than a kilometre from the race area, the reserve also protects the Caldara di Manziana, where a natural thermal spring discharges sulfurous water at 27 degrees Celsius. About thirteen kilometres away, the Riserva naturale regionale Monterano follows the Mignone river from the Sassone area to the tuff rock of Rota village. This reserve exhibits sulfurous springs and solfataric phenomena, including a spring active year-round where the Fosso della Palombara meets the Bicione stream. A thermal inversion keeps the valley floor of these river gorges cool and damp even through midsummer, providing habitat for the spectacled salamander, an endemic Italian terrestrial vertebrate living in the Bicione and Mignone gorges.

Former tuff quarries at Mercareccia have formed artificial ponds where little grebes and common moorhens nest. About fourteen kilometres from the race venue, the Treja river cascades over small waterfalls at Monte Gelato, channeled in part by human intervention to power a mill. The site holds deep historical layers, including a Roman villa constructed during the Augustan era that remained in use until the mid-4th century AD. During the Middle Ages, between the 11th and 12th centuries, the Castrum Capracorum was fortified here with a defensive moat at least four meters wide, alongside a 12th-century square tower designed to watch the river crossing. A water mill built in 1830 by the Del Drago family, likely over medieval foundations, operated its grinding stone at the waterfalls until the early 1960s.