Many significant things throughout history have been lost, inspiring archaeologists and treasure-hunters around the world to try to find them. The existence of some of these places or items, particularly those from ancient history, is legendary and remains in doubt.
- The RMS Titanic (lost 1912, found 1985)
- The Lost Legions Of Varus (Battle of the Teutoburg Forest) (last seen 15 AD, found 1987)
- Roman cities of Pompeii, Herculaneum, Stabiae, and Oplontis all buried in the eruption of Mount Vesuvius. (Lost 79 AD, rediscovered in 1748)
- The ancient city Troy (found by Schliemann, though this has been disputed) (found in the 1870s; lost 12th century BC–14th century BC)
- The Nuestra Señora de Atocha Spanish treasure ship lost 1622, found 1985.
- The Greek place of worship, Olympia (found by German archeologists in 1875)
Still lost - some are legendary or dubious
- Book of the Wars of the Lord, a non-canonical book possibly written by Moses, and the Israelites according to The Book of Jasher
- Ten Lost Tribes of Israel, lost following the invasion by Assyria in 722 BC
- The Lost Army of Cambyses — an army of 50,000 soldiers that disappeared in a sandstorm in the Egyptian desert (lost 525? BC)
- The lost dialogues of Aristotle (d. 322 BC)
- The Roanoke Colony of Roanoke Island, North Carolina (Lost 1587-88) Settlers of the first English colony in the New World vanish; leaving an abandoned settlement and the word "Croatoan," the name of a nearby island, carved into a post.
- The Money Pit on Oak Island
- The Mahogany Ship — an ancient shipwreck somewhere near Warrnambool, Victoria (Australia) (last seen 1880)
- The Lost Dutchman's Gold Mine (lost 1891)
- Victoria's Parliamentary Mace (lost 1891)
- The Amber Room (lost 1941?)
- Amelia Earhart and her aircraft (lost 1937)
- Flight 19 World War II era military aircraft training flight (lost 1945)
- FIFA World Cup Trophy Jules Rimet World Cup Trophy (lost 1983)
- Lost asteroids and planets, lost after having been once discovered (multiple incidents) — some rediscovered but others still lost
- The Holy Grail — biblical chalice
- Noah's Ark – biblical ship
- The Ark of the Covenant – biblical repository for the Ten Commandments
- The Lost City of Atlantis (lost??)
- The island of Atlantis described by Plato BC
- El Dorado: lost city of bountiful gold in the Americas.
- The Lost Ship of the Desert
- Missing Wonders: Many of history's most famous shipwrecks, tombs and relics are still missing By Jennifer Saranow, Wall Street Journal, November 9, 2007; Page W1