Late-antiquity and Medieval Fortress Momina Tower falls into the Pirin area of the Mesta river valley (Kremen village) - one of the narrowest and most picturesque stretches of Momina Klissura. Located on the west bank of Mesta River.

It was probably built in ІІ-ІІІ centuries, after which it was abandoned and restored only in the 12th century. The fortress is an archaeological monument of national importance and occupies an area of about 500 sq.m. From west the fortress wall is preserved and reaches a height of 8m. In this part was its only entrance. There are remnants of a rectangular tower measuring 5.40 / 6.20m in the eastern sector. Pieces of home ceramics typical of the V-VI and XII-XIV centuries are found. In the rocks beneath the fortress there is a natural cave proving the presence of a prehistoric settlement, but the entrances are masonry covered.