this part of their own country. Meanwhile, thousands of Armenians, Mingrelians, Greeks, Russians, Estonians, Germans, Moldovans and others who were resettled began from 1879 to take root here in today's Sukhum and Gulripsh districts. Religion Most of the inhabitants belong to the Orthodox and Armenian Apostolic Churches, Islam and the Abkhaz traditional religion. Culture Main sights Sukhumi theatres which offer classical and modern performances, with the theatre season lasting from September to June. Several galleries and museums exhibit modern and historical Abkhaz visual art. Sukhumi Botanical Garden was established in 1840 and is one of the oldest botanical gardens in the Caucasus. Sukhumi houses a number of historical monuments, notably the Besleti Bridge built during the reign of queen Tamar of Georgia in the 12th century. It also retains visible vestiges of the defunct monuments, including the Roman walls, the medieval Castle of Bagrat, several towers of the Kelasuri Wall, also known as Great Abkhazian Wall, constructed between 1628 and 1653 by Levan II Dadiani to protect his fiefdom from the Abkhaz tribes; the 14th-century Genoese fort and the 18th-century Ottoman fortress. The 11th century Kamani Monastery ( from Sukhumi) is erected, according to tradition, over the tomb of Saint John Chrysostom. Some from Sukhumi lies New Athos with the ruins of the medieval city of Anacopia. The Neo-Byzantine New Athos Monastery was constructed here in the 1880s on behest of Tsar Alexander III of Russia. Northward in the mountains is the Krubera Cave, one of the deepest in the world, with a depth of 2,140 meters. Education The city hosts a number of research and educational institutions, including the Abkhazian State University, the Sukhumi Open Institute and about a half a dozen of vocational education colleges. From 1945 to 1954 the city's electron physics laboratory was involved in the Soviet program to develop nuclear weapons. Additionally, the Abkhaz State Archive is located in the city. Until 19th century young people from Abkhazia usually received their education mainly at religious schools (Muslims at Madrasas and Christians at Seminaries), although a small number of children from wealthy families had opportunity to travel to foreign countries for education. The first modern educational institutions (both schools and colleges) were established in the late 19th-early 20th century and rapidly grew until the second half of the 20th century. For example, the number of college students grew from few dozens in the 1920s to several