Geography of Scotland example at Aberdeen. Much of the Scottish coastline consists of a machair formation, a dune pasture land formed as sea levels subsided. The east coast has several significant estuaries and other nature reserves including the Ythan Estuary and Fowlsheugh, both of which have been designated as Important Bird Areas. Firths of Scotland include the Solway Firth, Firth of Clyde, and Firth of Lorne on the west coast, and the Cromarty Firth, Moray Firth, Firth of Tay, and Firth of Forth on the east coast. The Pentland Firth is not an inlet, but the strait that separates the Orkney Isles from
Architecture of Scotland in the Roman era Elginhaugh fort, in Midlothian, dates to about this period, as may Castle Greg in West Lothian. The Romans eventually withdrew to a line in what is now northern England, building the fortification known as Hadrian's Wall from coast to coast. Around 141 CE the Romans undertook a reoccupation of southern Scotland, moving up to construct a new "limes" between the Firth of Forth and the Firth of Clyde. The resulting Antonine Wall is the largest Roman construction inside Scotland. It is a sward-covered wall made of turf, around high, with nineteen forts and extending for . The stone foundations and