Kyustendil is situated in the southern part of the Kyustendil Valley, 90 km south-west of Sofia.

Kyustendil is a national balneological resort at an altitude of 500 m. The town has a population of 54 000. The ancient name of the town Pautalia (a town of springs) is Thracian. The fortress was built by the Romans. Therms, basilicas, floor mosaics have been uncovered. In the 11th C. the town, known as Velbuzhd, after the name of its heir, Konstantin Velbuzhd, became a major religious and administrative center. About 1355 Velbuzhd and its region were included in the semi-independent feudal Velbuzhd principality of Despot Deyan.

In the 15th C. the town was called Kyustendil, which means a land of Konstantin. In 1372 the Turks conquered the town. During the Bulgarian National Revival crafts and trade flourished.

There are more than 40 mineral springs in the town. The waters are of considerable content of sulphide compounds. These are used for treatment of the locomotory system, gynaecological and other kinds of diseases. The resort region includes several baths, balneological complexes and others.

There are preserved historical monuments: St. George Church (approx. 11th-12th centuries), a medieval defence tower, named Pirkova Tower (14th C.), Fetih Sultan Mehmed (1531) and Ahmed Bei (1575) mosques, the Holly Virgin Church (1816) and St. Demetrius Church (1866), houses of the Bulgarian National Revival. On Hisarluka Hill there are remains of a fortress dating back to the 4th C., renovated under Justinian (6th C.).

Kyustendil has a historical museum and an art gallery with a rich collection of paintings by the great Bulgarian artist Vladimir Dimitrov Maistora.