Scotland during the Roman Empire of the geography of Scotland had extended to the "Hebudes" (The Hebrides), "Dumna" (probably the Outer Hebrides), the Caledonian Forest, and the Caledonians. Ptolemy, possibly drawing on earlier sources of information as well as more contemporary accounts from the Agricolan invasion, identified 18 tribes in Scotland in his "Geography", but many of the names are obscure. His information becomes much less reliable in the north and west, suggesting early Roman knowledge of these area was confined to observations from the sea. Famously, his coördinates place most of Scotland north of Hadrian's Wall bent at a right angle, stretching due eastward
Roman Wall (Sofia) notched brick cornice decorates the top of the wall. The Roman Wall was built in the 16th or 17th century, the time of the Ottoman rule of Bulgaria. The wall's exact purpose is unclear, though it is agreed that it performed an Islamic religious function. It may either be the preserved part of an eminent Ottoman Turk's tomb, or it may have formed part of a "namazgâh", an open-air religious structure where the imam would perform a prayer for those embarking on the Hajj. In the late 19th century, after the reestablishment of the Principality of Bulgaria in 1878, the