Ephesus (Turkish Efes) was an ancient Greek city on the west coast of present-day Turkey, near the city of Selçuk. Ephesus contains the largest collection of Roman ruins in the eastern Mediterranean. It is also the site of a large gladiators' graveyard. Only an estimated 15% has been excavated. The ruins that are visible today give some idea of the city's original splendor.

Ephesus was one of the twelve cities of the Ionian League during the Classical Greek period. The city was famed for the Temple of Artemis (completed around 550 BCE), one of the Seven Wonders of the Ancient World.

Ephesus was partially destroyed by an earthquake in 614. The city's importance as a commercial center declined as the harbor was slowly silted up by the Cayster River. This silt was likely due to erosion during ancient times brought about by deforestation and crude farming methods on adjacent hillsides. As the river Cayster silted up the harbor, the resulting marshes brought malaria and many deaths among the inhabitants. Weakened economically, Ephesus was unable to defend itself and suffered after being conquered my multiple empires. After loss of its important oceanfront position, plundering by passing armies, earthquakes and widespread illness, the city was abandoned in the 15th century. Crusaders, passing through, were surprised that there was only a small village, called Ayasalouk, where they had expected a bustling city with a large seaport. Even the temple of Artemis was completely forgotten by the local population.

Mankind's mark at Ephesus was simultaneously breathtaking and devastating. In ancient times an important port and commercial center, today Ephesus lies in ruins 3 miles from the Aegean Sea.

Ephesus was one of the seven churches of Asia that are cited in the Book of Revelation. The Gospel of John may have been written here.

The ruins of Ephesus are a favorite international and local tourist attraction, partly owing to their easy access from Adnan Menderes Airport and via the port of Kuşadası.