Portuguese explorer Diogo Cão travels down the coast of west Africa in the 1480s, becoming the first European to discover the Congo River, and setting the stage for others to round the tip of the continent.

See what happened to Lewis and Clark and the Corps of Discovery after the conclusion of their epic trek

The Corps heads out of the Rockies and down the Missouri - the last leg of their epic journey.

Lewis and Clark lead the Corps east - up the Columbia River and over the Rocky Mountains

Lewis and Clark fight their way across the Rocky Mountains and make for the Pacific Coast

Lewis and Clark struggle up the Missouri River and find that there is no easy route over the Rocky Mountains

In the late summer and fall of 1804, Lewis and Clark and the Corps of Discovery head into the lands of the powerful Sioux nation, aiming to reach the Mandan Villages, located near modern-day Bismarck, North Dakota.

In this episode, Lewis and Clark head up the Missouri River in the spring of 1804.

Meriwether Lewis and William Clark prepare to lead the Corps of Discovery west in an attempt to reach the Pacific Ocean

In the final part of our series, Nellie Bly sails from Japan in a last push to defeat Phileas Fogg - and her rival, Elizabeth Bisland.

Delayed ships, monsoons and other obstacles test journalist Nellie Bly as she travels from France to Asia,

Nellie Bly and the Race Around the World

In about 325 BCE Pytheas of Massalia begins one of the first great voyages of discovery when he sets out into the land of the Celts to find the legendary island of Britain.

In the final episode in our seven-part series on Christopher Columbus, the Admiral and his crew find themselves stranded on the island of Jamaica.

Columbus sets out on his fourth and final voyage. This time he's been ordered to find a passage to Asia - a voyage that will take him along the Central American coast.

In his third voyage to the New World, Christopher Columbus searched out the rumored lands to the south - and in the process, discover the South American continent.

Part 4 in our series on Christopher Columbus details his exploration of Cuba and Jamaica, plus his subjugation of Hispaniola.

Christopher Columbus heads to the New World for a second voyage. This time he has 17 ships and more than 1,200 men. The object is to establish a viable commercial enterprise in this newly discovered land.

Christopher Columbus sets off on his historic first voyage - one that would become the most important voyage of discovery in history.

Christopher Columbus tries to secure backing for an expedition to cross the Atlantic in a daring attempt to reach Asia.

Francisco de Orellana heads down the Amazon River in a desperate bid to return to civilization.

Francisco de Orellana and Gonzalo Pizarro head over the Andes in search of El Dorado - the City of Gold. Instead, they only find death, forcing Orellana to begin a desperate 4,000 mile journey down the Amazon to reach safety.

Zheng He commands the legendary Chinese Treasure Fleet, which sailed the Indian Ocean in the 15th century

Étienne Brûlé, the most famous of the Coureur de bois, explores the lands around the St. Lawrence River and the Great Lakes

In one of the greatest journeys of survival - and exploration - ever recorded, Álvar Núñez Cabeza de Vaca begins a 2,500 mile trek across Mexico in a bid to return to Spanish territory.