Gacko is first mentioned in the 12th century in the Chronicle of Priest of Duklja. It changed names since its foundation. One of them is i Metohija – which means church land. Throughout the history, a significant impact on this area was done by the Illyrians, Romans, Turks and Austro-Hungarians.

Traces of different cultural streams as a result of historical events have determined the course and forms of urban and cultural development until today. Cultural and historical monuments testify to the long and turbulent history of this region. In the area of Gacko municipality there are a large number of religious buildings, such as:

The medieval church of St. Nicholas in Srđevići – raised in the 14th century by princes and diplomats of Srđevići family, Gacko nobility, who played an important role in the medieval feudal society. Srđević nobility, from the period of Bosnian Duke Sandalj Hranić and Herceg Stefan, significantly affected the social and political circumstances of the time and  raised the in church frescoes as a sign of their power. The frescos which adorned the walls of the church are just the latest remaining reflection of the former significance of this place. Monastery Žitomislić keeps a 14th century Menaion (liturgical book), written on parchment for the church in Srđevići. After a lot of wandering with its text damaged and pages chopped the Menaion came to the monastery on the Neretva River where it is kept as a significant exhibit of the old spiritual life of Gacko.

– Saint Prince Lazar of Serbia Church in Pridvorica was built in 1936 and its restoration began in 2006. On Christmas Day 1942 the enemy killed about 180 villagers, including women, children and the elderly in the church. The remains of the martyrs were buried on April 17, 1942 in two graves near the temple and transferred to the temple crypt on 29 November 2006.

– The Church of Saint Demetrius in Domrke is one of the oldest churches in Gacko area. Folk tradition says the church was raised in the 13th century. Archaeological research has shown that the church was restored in 1883.

In the centre of the town is the new Cathedral Church of the Holy Trinity, as well as the old Cathedral Church of the Holy Trinity (the Descent of the Holy Spirit on the Apostles), built in 1884. It was renovated in the period 1962 – 1965 and 2004.

Medieval town of Ključ – not far from Gacko – built by the Zahumlje lord Sandalj Hranić in the fifteenth century, his most important city, where he issued the majority of his charters. His wife Jelena, the daughter of Prince Lazar and the widow of Balšić nobility, had a church built in front of the town. The fortress consists of the lower and upper town and its base is of rectangular shape. Ključ was one of the most significant towns in Herzegovina. Two cannons from the fort were transferred to the National Museum in Sarajevo.

– Stećci tombstones – Several thousands of silent ‘stone sleepers’ scattered in fields and hills speak in the stone language of man and life, which nameless stonecutters cut in signs and words to speak to generations to come.

Stećci spread over 114 sites, where there are about 2,200 of tombstones (stone slabs, chests, crosses) with 38 preserved inscriptions. A proof that these are the Orthodox monuments is the fact that, in many places, necropolises are located next to the medieval churches.

Gacko is also the cradle of Serbian spirituality and standardised language. Three distinguished men were born in Gacko: Sava Vladislavić – Raguzinski, Stojan Kovačević and Tešan Podrugović – Gavrilovic – epic bard of the Serbian people and the best narrator of epic folk songs recorded by Vuk Karadžić.