It has a crossroad position from Thrace to the Aegean Sea—part of European transportation route 9, via the Makaza mountain pass.

Exactly at noon, when the sun is highest in the sky, a ray of light comes in through a stone slit forming a falitic shade in the cave.

[5] There are many stone castles and palaces that the Thracians built in the region, including Perperek, Ustra, and Vishegrad.

The area was of strategic importance for the Bulgarian Empire during the Middle Ages and the remains of numerous Medieval fortress scattered on the surrounding hills can still be seen.

The town developed largely due to its position on the trade routes during the period of Ottoman rule.

The best known of these units was led by Pazvantoğlu Osman Pasha, who ruled most of the northeastern Ottoman lands and the Danube estuary until his death in 1807.

Kardzhali and its neighborhood became part of the autonomous province of Eastern Rumelia under the stipulations of the Berlin Congress of 1878, but, after the reunification of the Principality of Bulgaria and Eastern Rumelia in 1885, it was ceded back to the Ottoman Empire as a township of Gümülcine sanjak in Edirne vilayet.

Ottoman rule ended during the First Balkan War when the town and the surrounding area were liberated by the Bulgarian General Vasil Delov on 21 October 1912.

This included two emigration waves in the 1930s and 1950s as a result of treaties between Bulgaria and Turkey and most notably in 1989 in response to the state sponsored Revival Process which saw the forced Bulgarisation of ethnic Turks.

[11] The municipal government today is primarily in the hands of the Turkish-dominated Movement for Rights and Freedoms.

In response Turkish students boycotted schools until the ban on using their mother tongue was discontinued.

Formerly Kardzhali was a tobacco processing center, but for economic reasons all of the communist era industrial plants are no longer operative.

The large deposits of lead and zinc ore in the area once made the town an attractive location for the metallurgy and machine building industry.

However, in 2016 the no-longer-operative large Lead and Zinc Complex near the city met its final end with its two stacks being torn down.

This includes pre-historic tools and ceramics from the Thracian cities of Perperikon and Tatul, Christian icons and ethnographic exhibits.

[14] Longdistance hiking path the Sultans Trail passes Kardzhali dam, city center and many villages.

At maximum capacity, the waters of the Studen Kladenets Dam extend to the foot of the old Veselchane bridge.