The mausoleum was designed by architect Ilya Popov and was built in 1934. The building is built of stone, with a square shape that resembles a church. There is a dome roof, which has several windows. Vaulted portion is built of white stone from Vratsa. Inside of the mausoleum is decorated with frescoes. At the entrance to the mosaic was painted the portrait of Antim I. Inside is the sculpture of Antim I seated, and below, in the basement is a sarcophagus with his remains. In 1975, the mausoleum is declared a monument of culture.
Antim I was born in 1816 in Kırklareli, Eastern Thrace. He studied at Constantinople and Mount Athos, adopted in 1837. In 1856 he graduated from the Moscow Theological Academy and in 1868 was elected Metropolitan of Vidin. Here he was separated from the Patriarchate of Constantinople and began to fight for the independence of the Bulgarian church. After the establishment of the Bulgarian Exarchate in 1872, he was elected the first Bulgarian Exarch. Exarch Antim protested against the Batak massacre in 1876 and sent a letter to the Russian Tsar, outlining the difficult situation of Bulgarian nation and asked the king to plead for Bulgaria. For this activity Antim was ousted from the Gate and exiled to Asia Minor. After his release in 1878, following a general amnesty Antim became again an Exarch and participated in the construction of the new Bulgarian state. In 1879 he chaired the first National Assembly in Veliko Tarnovo, which chose Prince Alexander Battenberg as first Bulgarian prince. Exarch Antim later returned to Vidin, assuming leadership of the Vidin Diocese. He bequeathed his entire fortune to build the church of “St. Demetrius”, to build a community center and to develop educational activities in the two-storey building, a high school, which today bears his name. He died on December 1, 1888 in the town of Vidin. Near the mausoleum is the church of “St. Nicholas” and Pazvantoglu Osman Mosque.