Hadrian's Wall Marking The Boundary Between England And Scotland

HOUSESTEADS, UNITED KINGDOM - APRIL 17: Members of the public visit Hadrian's Wall at Sycamore Gap, a wall which was built in AD 122 on the orders of Emperor Hadrian to keep out the Picts from Scotland, on April 17, 2014 in England. A referendum on whether Scotland should be an independent country will take place on September 18, 2014. (Photo by Jeff J Mitchell/Getty Images)