Caspian Sea of around 149,200 square miles (386,400 square km)— bigger than the region of Japan—and its surface lies somewhere in the range of 90 feet (27 meters) below sea level. The sea bed in the southern part reaches as low as 1,023 m (3,356 ft) below sea level, which is the second lowest natural depression on earth after Lake Baikal (−1,180 m, −3,871 ft). The ancient inhabitants of its coast perceived the Caspian Sea as an ocean, probably because of its saltiness and large size. The sea has a surface area of 371,000 km (143,200 sq mi) (not including the detached
Prehistory of West Virginia physiographic province of the unglaciated Allegheny Plateau, which includes parts of the Allegheny Front and Ridge-and-Valley Appalachians. These western hills along the Ohio Valley climb east up tributary streams to the base of the Allegheny Mountains. The lowest altitude averages above the sea level, with the lowest point to the southwest along the Ohio River at below sea level. Below the eastern slopes of the Allegheny Front where approximately peaks stand, the Potomac River on the Eastern Panhandle of West Virginia flows along a plateau. The plateau reaches from southeastern Ohio through western West Virginia to the Ridge-and-Valley Appalachians, and