They are natural caves excavated by water located in Melilla La Vieja, which have access from the Museum of Sacred Art and are considered an Asset of Cultural Interest. They were used by Phoenicians, Romans, Arabs and finally by the Spanish. They have a gigantic open cavity, reinforced by a parabolic arch of stone and brick and 3 interconnected levels, from lowest to highest. The first consists of 2 intersecting naves and was used as a church, the second, a set of rooms connected to each other and with windows to the outside, the third being similar to the previous one, but with smaller and lower rooms.