The rock-church of Madonna de Idris was carved out of the rock face and partly rebuilt after the barrel vault collapsed some time before the beginning of the C14th. A small bell-tower rises from the building, lending balance to the complex. The church continued to function as a place of worship on certain feast days, until the 1940s.
The interior is extremely plain, with no architectural features worthy of note. The walls of the crypt were once richly covered with frescoes, some of which deteriorated through lack of attention and others were removed in the early 1970s by the Sovrintendenza per I Beni Storici ed Artistici (the Government body responsible for the country’s historical and artistic heritage) because they were in an appalling state of conservation and because of the high degree of humidity inside the church.
The C17th Madonna and Child on the altar is painted in tempera, a medium in which the colours were blended with gluey water, milk or egg white. The water pitchers on either side of them were known as idrie, which accounts for the Idris in the church’s name.
On the right there is a fresco of St. Eustachius, patron saint of the city and much venerated by the Materans, at the moment of his legendary conversion when, while out hunting, he espied a stag with a golden cross between its antlers. There is a stained glass window of this scene in the Cathedral and it is a subject that is repeated in frescoes in several rock-churches around the Sassi and the Murgia. On the right of this particular fresco, there is a painting of a Crib and St. Anthony, all of which date from the C17th.
Further along on the right, past the corner, there is rather crude crucifixion, interesting nevertheless because the outline of the ancient town of Matera is shown in the background. Below, the aperture of an ancient tank.
On the left of the altar is a painting of Our Lady of the Annunciation and on the wall next to that, on the left, is a badly decayed fresco of St Michael the Archangel trampling on the Devil, which is interesting in that the Devil is not depicted as a serpent as is more usual, but has human features.