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
Holland dunes consists of polder landscape lying well below sea level. At present the lowest point in Holland is a polder near Rotterdam, which is about below sea level. Continuous drainage is necessary to keep Holland from flooding. In earlier centuries windmills were used for this task. The landscape was (and in places still is) dotted with windmills, which have become a symbol of Holland. Holland is (land and water included), making it roughly 13% of the area of the Netherlands. Looking at land alone, it is in area. The combined population is 6.1 million. The main cities in Holland are