Banja Koviljača is a popular tourist town and spa situated in the Loznica municipality. It is the oldest spa in Serbia. Banja Koviljača is located on the west border of Serbia by the Drina river, 137 kilometres (85 mi) from Belgrade.

Banja Koviljača has a number of sulphuric and iron-bearing thermal mineral springs, ranging in temperature from 21 to 38 degrees Celsius. Patients drink and bathe in these waters, which are also used for the preparation of mud packs.

The location of the spa was chosen for its useful natural elements: the Drina river, which could be forded; the wooded mountain Gučevo, which served as shelter from enemies; the plains, which supplied food; and the water, which was (and still is) considered to have medicinal properties.

Gučevo is a wooded mountain which rises above the Banja Koviljača Spa to the south. The mountain extends from northwest to southeast and from Koviljača to the mountain Boranja. It is 15 kilometers long. The peak of the Gučevo Mountain is Crni Vrh, and its altitude is 779 m above sea level. Mount Gučevo is composed mainly of limestone and sand.

In the past, there was a terrain fissure on the mountain, which was significant to the occurrence of thermo-mineral waters. The mountain of Gučevo has many clear water springs which grow into smaller brooks overhung by high beech forests. The river Drina dominates the area and meanders between Mačva and Semberija.

Loznica is a city located in the Mačva District of the western Serbia. It lies on the right bank of the Drina river. Its name stems from the word "loza" (the Serbian word for vine). Originally, its name was Lozica (Serbian for small vine), but it later became Loznica.

Loznica has a humid subtropical climate with cold winters, often very cold due to the mountain winds of nearby mountains, and warm to hot summers. When hot air from Adriatic Sea starts going inland, to the north-east it rises over mountain barriers (Zlatar and Zlatibor), gaining jet effect and continuing fast to western parts of Serbia.

Among cultural heritage include the Church of the Holy Virgin located in the town, the 14th-century Čokešina Monastery, the 13th-century Tronoša Monastery, and monuments on Mount Gučevo, in Tekeriš, and in Draginac, as well as the ethnic village of Tršić.

A Serbian epic poem is the Battle of Loznica in which the central figure Anta Bogičević leads Serbian forces during the First Serbian Uprising. The most important local cultural event is "Vukov Sabor" (Council of Vuk) in Tršić, held annually in September, in memory of Vuk Stefanović Karadžić who was born in the village; it remains the oldest and largest cultural event in Serbia, for its importance and the increasing volume (20-30,000 visitors).