Namibia is one of the least crowded countries in the world. Only about 2.5 million people live in an area roughly twice the size of California. On March 21, 1990, Namibia gained its independence from South Africa. The country sits on the southwestern coast of Africa, bordered by the Atlantic Ocean to the west. Its most famous feature is the Namib Desert, one of the oldest deserts on Earth. Some of its sand dunes rise over 1,000 feet, making them among the tallest in the world. Despite the dry climate, Namibia has remarkable wildlife. The Etosha National Park is home to elephants, lions, rhinos, and hundreds of bird species. Namibia is also one of the few places where desert-adapted elephants survive, traveling long distances between water sources. The country's coastline is called the Skeleton Coast because of the many shipwrecks scattered along its foggy shores. The cold Benguela Current from Antarctica meets the warm desert air, creating thick fog that has confused sailors for centuries. Namibia's economy depends on mining, especially diamonds and uranium. The country is the world's fifth-largest producer of uranium, a metal used for energy production.