To circumnavigate a place, such as an island, a continent, or the Earth, is to travel all the way around it by boat or ship. More recently, the term has also been used to cover aerial round-the-world flights.

World circumnavigation
The map on the right shows, in red, a typical sailing circumnavigation of the world by the trade winds and the Suez and Panama canals; overlaid in yellow are the points antipodal to all points on the route. It can be seen that the route roughly approximates a great circle, and passes through two pairs of antipodal points. This is a route followed by many cruising sailors; the use of the trade winds makes it a relatively easy sail, although it passes through a number of zones of calms or light winds.
In yacht racing, a round-the-world route approximating a great circle would be quite impractical, particularly in a non-stop race where use of the Panama and Suez Canals would be impossible. Yacht racing therefore defines a world circumnavigation to be a passage of at least 21,600 nautical miles (40,000 km) in length which crosses the equator, crosses every meridian in the same direction and finishes in the same port as it starts. The map on the left shows the route of the Vendée Globe round-the-world race in red; overlaid in yellow are the points antipodal to all points on the route. It can be seen that the route does not pass through any pairs of antipodal points. Since the winds in the lower latitudes predominantly blow west-to-east it can be seen that there is an easier route (west-to-east) and a harder route (east-to-west) when circumnavigating by sail; this difficulty is magnified for square-rig vessels..
Since the advent of world cruises in 1922, by Cunard's Lanconia, thousands of people have completed circumnavigations of the globe at a more leisurely pace. Typically, these voyages begin in New York City or Southampton, and proceed westward. Routes vary, either travelling through the Caribbean and then into the Pacific Ocean via the Panama Canal, or around Cape Horn. From there ships usually make their way to Hawaii, the islands of the South Pacific, Australia, New Zealand, then northward to Hong Kong, South East Asia, and India. At that point, again, routes may vary: one way is through the Suez Canal and into the Mediterranean; the other is around the Cape of Good Hope and then up the west coast of Africa. These cruises end in the port where they began.

Aviation
There is one successful polar circumnavigation journey; tracing a great circle around the globe 'vertically' i.e. through both poles. Sir Ranulph Fiennes, Charles Burton and their team successfully completed the Transglobe Expedition between 1979 and 1982. Transglobe was the first polar circumnavigation by surface travel, touching two true antipodes: the two poles of the Earth. They approximated the great circle passing through Greenwich, covering 52,000 miles in the process. "To the Ends of the Earth" is the classic book which describes this journey.

Surface travel
Thomas Stevens was the first person to circle the globe by bicycle. The feat was accomplished between 1884 and 1886. While impressive at the time, a good portion of the trip was by steamer due to technical and political reasons.
The December 2006 guidelines issued by Guinness state that a human powered circumnavigation must travel a minimum of 36,787.559 km (the distance of the Tropic of Cancer), cross the Equator, and each leg must commence at the exact point where the last finished off. There are no requirements to reach antipodal points. To date no one has completed a human-powered circumnavigation according to the guidelines set by Guinness World Records.

Human-powered

Ferdinand Magellan, 1511–1521 (multiple voyages). In 1511 he visited the Moluccas (3°9′S 129°23′E). He returned to Portugal and set out in 1519 to circumnavigate the globe. He discovered and sailed through the Strait of Magellan and reached the Philippines in 1521, where he was killed on Cebu (10°5′S 123°33′E). It should be noted, however, that Magellan did not personally complete a circumnavigation of the Earth in any one single voyage.
Enrique of Malacca, ?–1521, Magellan's interpreter (multiple voyages). He was captured in Sumatra as a child and taken to the Moluccas where he was sold to Magellan in 1511; he accompanied Magellan on his circumnavigation and ended up on Cebu in the Philippines.
The 18 survivors of Ferdinand Magellan's expedition (which began with 5 ships and 200 men), 1519–1522, in the Victoria. After Magellan died in the Philippines in 1521, the circumnavigation was completed under the command of the Basque seafarer Juan Sebastián Elcano who returned to Seville on 8 September 1522 after a journey of 3 years and 1 month. Notable global maritime circumnavigations

Phoenician expedition sent by Pharaoh Necho II, c. 600 BC, first circumnavigation of Africa.
Roman Governor Gnaeus Julius Agricola, c. 80, first circumnavigation of Britain.
Jacques Cartier, 1534–1535, first circumnavigation of Newfoundland.
García de Nodal, 1619, first circumnavigation of Tierra del Fuego.
James Cook, 1769–1770, first circumnavigation of New Zealand.
Matthew Flinders, 1801–1803, first circumnavigation of Australia.
Adolf Erik Nordenskiöld, 1878–1879, first circumnavigation of Eurasia, via the Northeast Passage and the Suez Canal.
RCMP St Roch — first vessel to circumnavigate North America. 1940-1942, Vancouver to Halifax, Nova Scotia, via the Northwest Passage. 1950, Halifax to Vancouver, via the Panama Canal.
HMCS Labrador, 1954, first vessel to circumnavigate North America in a single voyage. Other notable maritime circumnavigations

Bruno Peyron (French), January–March 2005, fastest circumnavigation 50 days 16 hours 20 minutes 4 seconds.
Jean Luc van den Heede (French), 2004, fastest westward single-handed circumnavigation, 122 days 14 hours 3 minutes 49 seconds.
Adrienne Cahalan (Australian), February-March 2004, fastest woman to complete a circumnavigation (crew of "Cheyenne") 58 days 9 hours 32 minutes 45 seconds
Ellen MacArthur (English), 2004–2005, fastest single-handed 71 days 14 hours 18 minutes 33 seconds.
Jon Sanders holds the world record for completing a single-handed triple circumnavigation.
The RMS Queen Mary 2, at 148,528 gross tons, became the world's largest passenger ship to circumnavigate the globe during her 2007 world cruise. Notable aerial circumnavigations
The most famous circumnavigation never happened. This is the story told in Jules Verne's 1872 adventure novel, Around the World in Eighty Days. Upper class Englishman Phileas Fogg and his servant Passepartout use a variety of transportation means and ingenuity to accomplish the adventurous feat. The book was freely adapted by Mike Todd into an Academy Award winning movie of the same name in 1956, starring David Niven and Cantinflas. The book (especially) and the movie are tributes to the new transportation possibilities of the early Industrial Revolution, with the coming of steamships, railways, etc. As this circumnavigation did not cross the Equator or reach antipodal points, it would not have been recognized by Guinness Records as an official circumnavigation (if such a thing had existed at that time).