The Pont de Pierre meaning "Stone Bridge", is a Roman segmental arch bridge in the Italian

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 city of Aosta

Aosta

Aosta is the principal city of the bilingual Aosta Valley in the Italian Alps, north-northwest of Turin. It is situated near the Italian entrance of the Mont Blanc Tunnel, at the confluence of the Buthier and the Dora Baltea, and at the junction of the Great and Little St. Bernard routes...

 in the Aosta Valley. The bridge crossed the Buthier

Buthier

The Buthier is a mountain torrent in north-west Italy. A left tributary of the Dora Baltea, its entire course lies within the Valpelline valley, in the region of Aosta Valley.- Course :...

 about 600 m from the eastern exit of the Roman colony

Colonia (Roman)

A Roman colonia was originally a Roman outpost established in conquered territory to secure it. Eventually, however, the term came to denote the highest status of Roman city.-History:...

 Augusta Praetoria; in later times the torrente

Torrente

Torrente may refer to:* Torrent, Valencia, a municipality located within the metropolitan area of the city of the Spanish city Valencia* Torrente , a Parisian haute couture fashion house founded by designer Rosette Torrente-Mett in 1969; current creative director Julien Fournie* Gonzalo Torrente...

 changed its course, leaving the ancient

Ancient history

Ancient history is the study of the written past from the beginning of recorded human history to the Early Middle Ages. The span of recorded history is roughly 5,000 years, with Cuneiform script, the oldest discovered form of coherent writing, from the protoliterate period around the 30th century BC...

 bridge today without water.

The single-arch bridge has a span of 17.1 m and a width of 5.9 m. The arch vault consists of large voussoir

Voussoir

A voussoir is a wedge-shaped element, typically a stone, used in building an arch or vault.Although each unit in an arch or vault is a voussoir, two units are of distinct functional importance: the keystone and the springer. The keystone is the center stone or masonry unit at the apex of an arch. A...

s and shows a comparatively flat profile (span to rise ratio 3:1). The facing was built of pudding stone

Puddingstone (rock)

Puddingstone, also known as either Pudding stone or Plum-pudding stone, is a popular name applied to a conglomerate that consists of distinctly rounded pebbles whose colors contrast sharply with the color of the finer-grained, often sandy, matrix or cement surrounding them...

, the spandrel

Spandrel

A spandrel, less often spandril or splaundrel, is the space between two arches or between an arch and a rectangular enclosure....

s filled with Roman concrete.

The structure is dated to the second half of the reign of Augustus

Augustus

Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

 (30 BC–14 AD), who had earlier founded the military colony Augusta Praetoria at an important road junction (24 BC). The Pont de Pierre was of particularly strategic importance, since in Aosta the transalpine routes to Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

 branched off into the Little St Bernard

Little St Bernard Pass

The Little St Bernard Pass is a mountain pass in the Alps on the France–Italy border. Its saddle is at 2188 metres above sea level. It is located between Savoie, France and Aosta Valley, Italy to the south of the Mont Blanc Massif, precisely on the main alpine watershed. There is also a Great St...

 and the Great St Bernard Pass. In southeasterly direction towards the Po Valley

Po Valley

The Po Valley, Po Plain, Plain of the Po, or Padan Plain is a major geographical feature of Italy. It extends approximately in an east-west direction, with an area of 46,000 km² including its Venetic extension not actually related to the Po River basin; it runs from the Western Alps to the...

, the road led over another segmental arch bridge, the excellently preserved Pont-Saint-Martin Bridge

Pont-Saint-Martin Bridge

The Pont-Saint-Martin is a Roman segmental arch bridge in the Aosta Valley in Italy dating to the 1st century BC.The span is according to recent research, but frequently stated to be 35.64 m or 36.65 m....

, located at the exit of the Aosta valley.

External links

• Traianus – Technical investigation of Roman public works