The picturesque village, whose origins are linked to the development of an agglomeration around the hermitage of the Irish monk Ursicinus, preserves a fascinating example of medieval and Renaissance architecture.

The layout of the houses still follows the course of the fortified walls, which separate the 13th-century town from the rest of the village, centred around the church. The street network, which develops in a linear fashion to the east, was created following the fire that devastated the area in 1403. The town gates, which mark the main entrances, were rebuilt in the 16th and 17th centuries and bear witness to the transition from the medieval to the Renaissance structure. The ‘Porte Saint-Pierre’, located at the eastern entrance, retains its medieval lower structure and is surmounted by a pavilion roof with a bell tower, added in 1552 and renovated in 1665. To the west, the ‘Porte Saint-Paul’ (also known as the ‘Porte de Porrentruy’) was completely rebuilt in 1664. The southern entrance is the ‘Porte Saint-Jean’, which also serves as the bridgehead for the bridge over the Doubs. A central element of the village is the Collegiate Church, a Romanesque basilica distinguished by its pillared nave without transept. The aisleless crypt, located below the choir, dates back to the 12th century. The nave retains the typical characteristics of Romanesque churches in Burgundy and Franche-Comté, while the bell tower, located on the façade, is a reconstruction from 1442. The south portal of the church is inspired by the St. Gallen gate of Basel Cathedral. The Town Hall, renovated in 1825, retains the ground floor of the former Gothic building, characterised by a pillared portico with ribbed vaulting, which adds a touch of historical elegance to the central area of the village. This mix of medieval, Renaissance and Gothic architecture gives the town a unique charm, reflecting its long and varied history.