Minas Tirith had seven walls: each wall held a gate, and each gate faced a different direction from the next, facing alternately somewhat north or south. Each level was about higher than the one below it, and each surrounded by a high stone wall colored in white, with the exception of the wall of the First Circle (the lowest level), which was black, built of the same material used for Orthanc. This outer wall was also the tallest, longest and strongest of the city's seven walls; it was vulnerable only to earthquakes capable of rending the ground where it stood. The Great Gate of Minas Tirith, constructed of iron and steel and guarded by stone towers and bastions, was the main gate on the first wall level of the city. In front of the Great Gate was a large paved area called the Gateway. The main roads to Minas Tirith met here: the North-way that became the Great West Road to Rohan; the South Road to the southern provinces of Gondor; and the road to Osgiliath, which lay to the north-east of Minas Tirith. Except for the high saddle of rock which joined the west of the hill to Mindolluin, the city was surrounded by the Pelennor, an area of farmlands.