Boussac-Bourg was formerly called Boussac the churches because of its peculiarity of having 2 churches, today known as the Saint-Martin Church and the Notre Dame Chapel.
The two "twin" churches presented a curious disposition, built at the same time, parallel to each other. They were connected by a passage. It seems that the smallest, with a steeple, was at the parish; the other, larger and without steeple, was to be the church of the priory dependent on the Provost of Evaux.
From these two churches there is, to the north, the most important, single nave, terminated by a narrower choir and a circular apse. The second is in ruins, the nave destroyed, the vaulted choir is on a square plan and supports the steeple. Inside, there are important remains of superimposed frescoes from the 12th-13th century and the 15th century.
Classified Historical Monument in 1930