Zemen (Bulgarian: Земен [ˈzɛmɛn]) is a town in Pernik Province, western Bulgaria. Located near the Pchelina Reservoir on the banks of the Struma River, it is the administrative centre of Zemen Municipality.

Zemen is located in a mountainous region in southwestern Bulgaria. It is located 70 km from Sofia, almost halfway between Radomir and Kyustendil. It is located on both banks of the Struma River, in a small valley, which is a prelude to the Zemen Gorge, near the Pchelina Dam. Its old name was Belovo. The name Zemen was originally given only to the railway station built on his land, and in 1925 the village of Belovo was renamed the village of Zemen. The proponents of this name had in mind to revive and preserve the name of the medieval Zemlengrad, which existed not far from the place of the present city of Zemen in the gorge of Struma. Since 1974 Zemen has been declared a city and is now the territorial-administrative centre of the Zemen municipality of Pernik region.

In Zemen the climate is humid-continental (Dfb), and the mountains determine the climate with a mountainous character. Temperature inversions also occur.

In the second half of the second millennium BC. Thracians from the Peoni, Agriani and Dentheletae tribes settled in the lands of the middle course of the Struma River. The Dentheletae inhabit the lands in the Kyustendil region. The Ileans founded the city of Alea [Ælea] and remained until the arrival of the Romans. Around 429 BC. the ileas are subordinated to the Odrysian king Sitalces (440 - 424 BC). After his death, the Lei entered into an alliance with the stronger neighboring Thracian tribes Agriani and Peoni. The Thracian tribe Lei settled in the agricultural lands in V BC. and remained until the coming of the Romans. Evidence of the presence of Thracian tribes in the Zemen region are finds of coins, votive tablets of Thracian horsemen, jewelry and remains of pottery / marble slabs of the daughter of the Thracian military leader Mucatralis, votive plaque depicting the Thracian goddess Bendis, ancient Mitra et al. Until the age of 45, the lands of the lands were part of the Thracian settlement system Dentelatika. After the fall of Thrace under Roman rule, the lands of the lands entered the boundaries of the large city centre Pautalia (today's Kyustendil). In Late Antiquity (II - IV century), the Romans created a settlement system within the boundaries of today's land. They were engaged in agriculture, winemaking and gold. There is a large number of Roman fortresses built in hard to reach places. Remains have been found in Roman forts - jars, aqueducts, Roman coins / of Emperor Justinian / and tiles dedicated to Roman deities. No written record of Roman settlements has been found. Slavs from the Strimonci tribe (Strumci) lived in the Zemen region. In a map of the Velbuzhd region from the Middle Ages on the territory of the town of Zemen is marked the settlement of Belovon.

During the Middle Ages in the Struma Gorge, in the vestibule of Velbuzhd, the fortress Zemlengrad was built. Konstantin Jireček spoke about it for the first time in "Journey through Bulgaria". Describing in a unique way the beauties of the Zemen Gorge, Jireček tells about interesting historical events that took place in these lands:

Here a magnificent rocky amphitheater opened, on the slopes of which there were still numerous small caves. From the right bank a long stony protrusion protrudes to the southeast and at the end, about 100 m above the surface of the Struma, the stone foundations of a spacious town are peeled off on a hard-to-reach hammer. It is called Zemensko Kale, this whole impassable area in the narrows of Struma from Belovo to Rust is called by the population Zemen. This is Zemlengrad, more often mentioned in the South Slavic monuments from the XII-XIV century. To the west, the fortress wall descends very steeply to the river…

During the Ottoman rule, and especially after the advent of firearms, the Struma Gorge between Zemen and Razhdavitsa lost its former military-strategic significance, but its relatively good passability remained. The economic role expanded in this part of the Ottoman Empire - he became the most direct route for people and goods. The villagers of Belovo were obliged to assist the security posts in the gorge. The abandonment of the medieval church and the abandonment of the village cemetery around it suggest that the village may have been depopulated for some time, for reasons unknown at the time during the Ottoman rule. Then gradually new people came and settled here again. During the hajduk time in the mountains around Belovo, the hajduk companies of famous voivodes roamed in this area. Some of their names have come down to us, but there are many that history has forgotten. In the last years before the Liberation, an attempt was even made to overthrow the Turkish government, but it failed because the organizers were betrayed to the Turks.

The liberation of Bulgaria from Ottoman rule caused a sharp change in Kyustendil and its surroundings. The Turkish population, officials, military, merchants and police fled. The liberated Bulgarians no longer had anyone to deliver the products from the Turkish properties. Goods were no longer transported through the passage. The merchants passed along the newly built convenient road Kyustendil - Radomir through the Konyavska mountain. Thus, for almost three decades, Belovo found itself in great isolation and during that time no tangible changes took place in it. Tucked away at the foot of the surrounding mountains, cut off from busy roads, surrounded and separated by the turbulent waters of the Struma for most of the year, it continued its idyllic existence. Active economic relations with the surrounding and more remote villages were not maintained.