In the latitude of southern New York the crystalline rocks are compressed into narrow compass and lose their mountainous character. They form the irregular hills on which New York City itself is built and which make the suburbs of Westchester County along the eastern Hudson so diverse and beautiful. To the southeast the topography of the old crystalline band becomes still less pronounced, as may be seen in the rolling, fertile hills around Philadelphia. Farther south the band divides into two parts, the mountains proper and the Piedmont plateau. The mountains begin at the Blue Ridge, which in Virginia raises its even-topped heights mile after mile across the length of that State. In North Carolina, however, they lose their character as a single ridge and expand into the broad mass of the southern Appalachians. There Mount Mitchell dominates the eastern part of the American continent and is surrounded by over thirty other mountains rising to a height of at least six thousand feet. The Piedmont plateau, which lies at the eastern foot of the Blue Ridge, is not really a plateau but a peneplain or ancient lowland worn almost to a plain. It expands to a width of one hundred miles in Virginia and the Carolinas and forms the part of those States where most of the larger towns are situated. Among its low gentle heights there rises an occasional little monadnock like Chapel Hill, where the University of North Carolina lies on a rugged eminence which strikingly recalls New England. For the most part, however, the hills of the Piedmont region are lower and more rounded than those in the neighborhood of Philadelphia. The country thus formed has many advantages, for it is flat enough to be used for agriculture and yet varied enough to be free from the monotony of the level plains.