The ancient city of Klos (Nikaia) it is situated in the proximity of Byllis (ca.1 km), with a wall about 1850m long, covering an area of ca.18 ha.
The wall represents one of the earliest fortifications of the second half of the 5th century B.C. in Albania, being 3-3.5m wide, with polygonal and trapezoidal blocks. There is a single entrance to the city and three defensive towers. Among the most important monuments are the small theatre, a stoa, and the traces of a stadium. The theatre had a capacity of ca. 800-1000 spectators and has preserved also 14 citizenship-granting inscriptions, dating to the 3rd century B.C. The stoa was long 40m and 10m wide, being a simple one story building. Life in Nikaia ends abruptly in 167 B.C., when the army of Paulus Aemilus ravaged Epirus
and parts of Southern Illyria.This town was built in the second half of the fifth century B.C., on the slanting slopes of a hill and connects to Bylis through a pass.
The surrounding wall, which is 1850 m long and 3-3.5m wide, encompasses the hill with a surface area of 18 ha. Three defense towers are located next to the only entrance of the town. The town contains the archshaped theater, which was built on a rock formation with a capacity of 800-1000 seats. Fourteen decrees for granting citizenship are engraved on the surrounding walls of the theater. They date back to the second half of the third century B.C. The stoa (with an open side of pillars) is partially excavated and shows a length of 40 m and a width of 10 m.