The town of Hissarya lies at a distance of 42 km north of Plovdiv and has a population of 8 000 inhabitants. The town is the centre of a municipality with 11 component settlements. The settlement is situated at the southern slopes of the Sashtinska Sredna Gora Mountains at an altitude of 364 m. Hissarya is a national spa resort. The mineral springs are with a capacity of 5 000 litres per second and a temperature of 37-51^oC. The town has more than 20 mineral springs suitable for the treatment of kidney and liver diseases and rheumatism.

The favourable climate and the mineral waters have attracted people to these lands since ancient times. A settlement has existed in the region since V-IV c. B.C. Later it has entered the limits of the Odrysian state. From this period are the great cult monuments by the village of Starossel at a distance of 20 km from Hissarya. After the conquering of the Thrace Province by the Romans in 46 a big Roman settlement is founded in the region. The emperor Diokletzian gives it the statute of a town and names it after himself. During the barbarian invasions this town is demolished and in VIII-X c. on the site is founded a Bulgarian settlement with the name of Topolitza. During the Ottoman invasion the settlement is demolished and many of its inhabitants are killed. The town is mentioned in the Ottoman documents in 1576. The settlement has been proclaimed for a town in 1964.

The tourist sights of the town are: the remains of the ancient town, the churches "St. Dimiter" (1845-1882), "Uspenie Bogorodicho"/The Assumption/ (1883), "St.St. Peter and Pavel" (1882) and the Thracian cult centre of Starossel.

Tourist sights

The Thracian cult centre of Starossel is a grandiose cult centre from the end of V and IV c. B.C. The monument has been discovered in 2000 and consists of 8 mounds of different sizes.

The Chetinyov's mound at the village of Starossel is a Thracian temple. The temple is 20 m high with a diameter of 85 m. It is surrounded by an impressive fence of 241 m length and preserved height of 3,5 m. The entrance of the sanctuary is 1,60 m wide with a decoration known as "wolf's teeth". The entrance has slabs of plastic and floral design. The temple consists of a southern parade staircase, two side staircases, a 10 m long and 6 m wide corridor, precise façade, rectangular and round chamber with dome roof with a diameter of 5,40 m. The temple is built of well-formed stone blocks connected by lead-poured iron braces. More than 4 000 huge stone block have been used for the construction of the temple. The temple is one of the most impressive in the Thracian lands. There are hypotheses that here has been buried the greatest king of the Odrysian kingdom - Spartacus. The temple is the key monument of a huge cult centre with many other rocky sanctuaries and dozens of mounds.

The Horizon mound lies at a distance of 2 km north of the village of Starossel. The Thracian temple has been built in V c. B.C. It is built of well-formed stone blocks connected with iron braces. The façade and the transverse corridor have been outside of the mound while the narthex and the rectangular chamber have been under the mound. The visible part of the temple is with 6 columns at the front and 2 at each side of an early Dorian style. The temple has been transformed into a mausoleum in the middle of IV c.

The Nedkov's mound at the village of Panicheri lies on the border of the cult centre of Starossel. The temple dates back to V c. It is built of white lime and dark granite blocks connected by lead-poured iron braces. The temple has been transformed into a mausoleum of the Thracian ruler of the time in IV c. The temple consists of a narthex and a rectangular chamber. The floors are covered with well-formed and well-arranged stone slabs. The roof is from huge cross-beams of alternating dark granite and white lime. Some ritual pits have been discovered of which 23 have been studied. Five of them are in front of the temple and are arranged as the Olympic rings.

The Peichov's mound in the village of Starossel dates back to IV c. The chieftain buried in the mound is a follower of Orpheus. His body has been segmented and buried next to a rock. Close to the rock has been built a camber with a double-layer roof with the belongings of the chieftain.

The Mavrov's mound in the village of Starossel is part of the Thracian cult centre. Here have been discovered a gold seal-ring, a glass mask of a human face, a bronze mirror and other objects.

The ancient town of Diokletzianopol/Hissarya/ has been the third in size in the Thrace Province. The favourable climate and the mineral waters have attracted people to the site since ancient times. A settlement is found to have existed from V-IV c. B.C. Later the settlement enters the limits of the Odrysian state. From this period are also the great cult monuments by Starossel at a distance of 20 km from the town.

After the conquering of the Thrace Province by the Romans in 46 a big Roman settlement is founded in the region. The emperor Diokletzian gives it the statute of a town and names it after himself. The town is one of the most well-preserved monuments of that time. At some places the fortified walls reach a height of 11 m and in the southern part -13 m. The complex of buildings has been concentrated in the centre - there has been an amphitheatre, a residence, a public bath of 2000m^2. The amphitheatre is of the type of the circuses where sport competitions and animal fights have been held. In the public bath of Diokletzianopol have been performed medical procedures and mineral water treatment. They have been of white marble and heated with the hot water from the mineral springs. They impress with their originality. Diokletzianopol has been one of the favourite recreation sites. There is historical evidence that the emperor himself have been a guest of the town at least twice.