Église Saint-Denys, Church in Le Thillay, France

Église Saint-Denys is a Catholic parish church in Le Thillay, Val-d'Oise, built almost entirely in the 16th century in a restrained Flamboyant Gothic style. Its plan is irregular: a five-bay nave with a single aisle on the north, a tower at the south of the first bay, and the Saint-Nicolas chapel along the last two bays. The tower rises in light gray and tan stone, buttressed at its corners, into a slate spire with a small lantern and cross; a lower red-tiled roof adjoins it. Inside, pointed ribbed vaults rest on tall round piers with carved capitals, and rows of slatted wooden chairs flank a central aisle of large irregular stone slabs leading to the altar and stained-glass windows.

The parish is not mentioned before the 13th century, and the present building goes back mainly to the 16th century as part of the reconstruction after the Hundred Years' War. A first consecration took place in 1545, then a second in 1583 when the ribbed vaulting and its carved keystones were finished.

The church is named after Saint Denis, but the Paris bishop, not the abbey of Saint-Denis, held the right of presentation to the cure from the 13th century onward. The parish now forms a group with Fontenay-en-Parisis, Goussainville and Vaud'herland, and Sunday mass is normally celebrated here at 9:30, with some restrictions in July and August.

The entrance is on the west side and gives onto a single aisle along the north, with a short chapel on the south side, so the interior is easy to walk through without getting lost. Since the floor is stone, shoes with a good grip help, especially on damp days.

The plan is irregular, with only one aisle on the north and a short chapel on the south, which gives the interior an unexpected asymmetry. The keystones above the vaults carry carved details from the Renaissance, a rare decorative touch in an otherwise plainly built church.