The National Archaeological Museum, in the centre of Sofia, occupies the building of the largest and oldest former Ottoman mosque in the city, originally known as Koca Mahmut Paşa Camii. The construction started in 1451 under grand vizier Veli Mahmud Pasha but due to his death in 1474 the mosque has been completed in 1494. The museum was established as a separate entity in 1893 as the National Museum directed by Czech Václav Dobruský with its headquarters in the former mosque that previously housed the National Library between 1880 and 1893.
Prehistory Hall displays a collection of items dating from between 1,600,000 BC and 1,600 BC. The collection is chronologically displayed and includes various findings from caves around Bulgaria, tools of the earliest humans who inhabited its modern territory, drawings, simple pottery, ritual items and many others.
Treasury displays grave inventory and other treasures from the late Bronze Age to late Antiquity. Two of the most well-known Bulgarian treasures are located here: the Valchitran and Lukovit Treasures. Main Hall hosts a collection of diverse items ranging from ancient Thrace, Greece and Rome to the late Middle Ages.
The medieval Section includes a gallery of medieval books, woodwork, drawings, metal objects and other items characteristic of the era.
The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.