Remains of a fortress are found about 4 km from Pchelarovo, in Gradishteto area ( right from the road to Haskovo). The fort is dated back to the Middle Ages, but archaeological excavations of the site revealed that it was built on the foundations of a much older cultural stratum dated to 3500 BC. (Stone-Copper Age).
The fortress near Pchelarovo is in the form of an ellipse with diameters 75 and 22 meters. It is located on a low, but dominating over the surrounding area, hill. The west and south part of the fort are steep and naturally protected by steep cliffs. The most accessible was the north side. A protective wall was built there, which was 32 meters long and 1.2 - 1.5 m thick, built of roughly shaped pebbles cemented with Kalov solution.The wall started from a cliff in the south, continued to the north and made a twist in the middle. A security tower with a diameter about 3.4 meters was built in the resulting twist.
Many religious objects as well as tools of bone, ceramics and metal were found during archaeological excavations. A unique collection of 57 ceramic and marble idols has been found. In this region, archaeologists found a copper sculpture of a Thracian horseman. Hence comes the conclusion that life in this place existed since antiquity.
No buildings were found in the fortress area, except for a small building in the south, which could have been a chapel. Outside the fort were discovered other archaeological sites - an ancient necropolis by the river, foundations of a monastery, parts of an ancient road, prehistoric mounds and others.