This commune covers an area of 13km² and has around 315 inhabitants who are known as ‘Montreuillois’. It is located just under 25 minutes south-east of Troyes. Reached via the D106, D57 or the D143, it is 11 minutes from junction 23 (Thennelières) of the A26 between Calais and Troyes.

Montreuil-sur-Barse has a primary school. It is one of the communes of the Forêt d’Orient Regional Nature Park. Its historic heritage, natural environment and the commune's recent economic development make it a unique place to live. Its beautiful brick and timber-framed rural cottages add to the rustic feel of the Auboise countryside, with its abundant vegetation typical of the ‘champagne humide’ area.

In the middle of the village, Rue du 27 August 1944 leads to the church of Saint-Gilles. The square marked out by the base of the bell tower, the short nave and the low porch are elements of its Romanesque architecture (10th - 12th century) that have been preserved. The rest of the building was added in the 16th century without compromising the original structure. The preservation of parts of the building dating from different centuries led to it being listed as an historic monument in 2002. Some of the church furnishings are classified or listed as historic monuments, including a 17th-century oak eagle lectern, an 18th-century gilded oak monstrance stand, a polychrome limestone Christ in Chains from the 16th century, and several oil paintings on canvas dating from the 17th, 18th and 19th centuries including a Saint Nicolas by Viard.

In the same road, there is a memorial bearing the names of 15 people who were executed on 27 August 1944. A few metres away, an iron soldier stands on a plinth commemorating the victims of the 1870 Indochina War and the First and Second World Wars.