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 period. There is also evidence of distinctive stone wheelhouses and small underground souterrains. From about 71 CE the Romans began military expeditions into what is now Scotland, building forts, like that at Trimontium, and probably pushing north as far as the River Tay where they created more fortifications, like those at Inchtuthil. These were soon abandoned, and the Romans settled for the occupation of the Southern Uplands by the end of the first century, below a line drawn between the Tyne and Solway Firth. This resulted in more fortifications and the building of Hadrian's Wall across what is now northern