First and the main stop for the tour. The biggest and most important orthodox cloister in the country. The monastery was built on the site of an old post house in 927 - 941 by St. John of Rila the Wonderworker (according to some authors - by his students) in the Rila mountain. In the courtyard of the present monastery, in 1335, a defense tower and a small one-nave church were erected by the local feudal lord Protosevast Hreljo. The tower is the oldest preserved building in the monastery complex. At the top of the tower is the "Holy Transfiguration" chapel with valuable frescoes from the 1430s. On September 21, 1378, King Ivan Shishman (1371 – 1393) issued the Rila charter, signed and sealed with a golden seal, giving the monastery 20 villages as feudal possessions, together with their lands.

Located on the outskirts of Sofia, Boyana Church consists of three buildings. The eastern church was built in the 10th century, then enlarged at the beginning of the 13th century by Sebastocrator Kaloyan, who ordered a second two storey building to be erected next to it. The frescoes in this second church, painted in 1259, make it one of the most important collections of medieval paintings. The ensemble is completed by a third church, built at the beginning of the 19th century. This site is one of the most complete and perfectly preserved monuments of east European medieval art.