Search the Discovery Encyclopedia

Natural wonder Volga The Volga is Europe's longest river. It rises in the Valdai Hills northwest of Moscow and flows about 3,530 kilometers to the Caspian Sea, all within Russia. Almost half of Russia's people live in its basin. Big dams now turn much of it into a chain of long lakes, and its huge delta shelters up to 750,000 waterbirds in mild winters.
Country Senegal Senegal is a country at the far western tip of Africa, on the Atlantic Ocean. Its capital, Dakar, sits on the westernmost point of the continent. About 19 million people live there, and the Senegal River, wetlands full of birds and quiet mangrove deltas make it a place of water as well as dry grassland.
Natural wonder Pantanal The Pantanal is one of the world's largest freshwater wetlands, mostly in Brazil and reaching into Bolivia and Paraguay. Each rainy season its rivers overflow and flood the lowlands, making shallow lakes and marshes; in the dry season the water slowly drains away. This rhythm feeds an amazing number of animals, from jaguars and giant otters to about 600 kinds of birds.
Country Mauritania Mauritania is a large country in northwest Africa where the Sahara meets the Atlantic Ocean. Dunes cover about half the land, ancient trading towns stand by desert oases, and many kinds of migrating birds spend the winter on its coast. About 5.3 million people live there.
Country The Gambia The Gambia is the smallest country on Africa's mainland, a narrow strip of land on both banks of the Gambia River. Except for a short Atlantic coast, it is surrounded by Senegal. More than 500 kinds of birds live there, and about 2.8 million people lived there in 2025.
Natural wonder Mississippi River The Mississippi River flows about 3,770 kilometers from Lake Itasca in Minnesota to the Gulf of Mexico, through the middle of the United States. Its basin drains about 40 percent of the continental United States. Long ago Native Americans paddled canoes on it; later came steamboats, and today huge barges carry grain and fuel. Millions of birds follow it when they migrate.
Geography River deltas A delta is land a river builds where it slows down and empties into a sea, a lake or another river. The slowing water drops its sand and mud, which pile up into low, flat, watery land. Many deltas are fan-shaped, like the Greek letter delta (Δ), but some look like a bird's foot.
Natural wonder Danube The Danube is Europe's second-longest river, after the Volga. It begins as two small streams in Germany's Black Forest and flows about 2,850 kilometers east to the Black Sea, passing through 10 countries and four capital cities. For more than 2,000 years it has been a border, a highway for boats and a home for wildlife, and it ends in a giant delta of reeds, lakes and birds.
Natural wonder Virunga National Park Virunga National Park, in the east of the Democratic Republic of the Congo, was founded in 1925; the park describes itself as Africa's first national park. It stretches from active volcanoes in the south to the snowy Rwenzori Mountains in the north. About one third of the world's mountain gorillas live in its forests, along with elephants, hippos, chimpanzees and hundreds of kinds of birds.
Natural wonder Everglades National Park Everglades National Park covers 1.5 million acres at the southern tip of Florida. It protects marshes of sawgrass, forests of mangroves and pines, and shallow bays, all fed by fresh water flowing slowly south. It is home to alligators and crocodiles, the rare Florida panther and hundreds of kinds of birds, but invasive Burmese pythons have caused serious harm to its wildlife.
Journey The first voyagers of the Pacific Over thousands of years, the ancestors of today's Pacific Islanders sailed double-hulled canoes across the Pacific and settled islands from Samoa and Tonga to Hawaiʻi, Rapa Nui and Aotearoa New Zealand. They had no compasses or maps: navigators read the stars, the ocean swells, the clouds and the birds.