Baltimore lies in an arm of the Chesapeake Bay, the
third largest estuary in the world. The eastern two-thirds of the metropolitan
area lie on the Atlantic Coastal Plain, between 15 and 50 feet above sea level,
and contain many peninsulas jutting out into the bay. The western third of the
city slowly rises into rolling hills, and leads to the piedmont region. It is
located about 40 miles from Washington, D.C., and approximately 100 miles from
Philadelphia. The Atlantic Ocean lies about 2 hours to the southeast.
