Londonderry is often referred to by its original name, Derry, meaning oak grove; the prefix "London" was added in the 17th century when large areas in the north of Ireland were granted to the London livery companies for development. The old city, which stands on a hill on the west bank of the River Foyle, is still surrounded by its 17th century walls. The Sperrin Mountains rise to the northeast of the city while the mountains of Donegal lie to the west and north.