The ruins of Lutitsa fortress are located south-west of town of Ivailovgrad. In the past Lyutitsa was a medieval fortress - one of the largest in the Eastern Rhodopes, known as "Marble town" and "The Citadel of Kaloyan". In that times Lyutitsa was a big and rich town - center of episcopate (IX - XVII century) and the Archdiocese (XVII - XVIII century). It was played an important role in Bulgarian history during the reign of Kaloyan.
The basic construction dates back to IV - VI century and the fortress existed until the end of XVIII century, when it losing its significance as a fortification facility and its residents created a new village of Ladzha outside the fortress, near the mineral springs.
The citadel has a form of irregular ellipse. The walls are 600 meters long and 10m in height . 8 of all 12 towers of the fortress are still well preserved.
Nowadays Lutitsa fortress is declared archaeological monument.