Ephesus,was located in Ionia, where the Cayster River (Küçük Menderes) flows into the Aegean Sea. It was part of the Panionian League.

Today's archaeological site lies 3 kilometers south of the Selçuk district of İzmir Province, Turkey. The ruins of Ephesus are a favorite international and local tourist attraction, partly owing to their easy accessibility from Adnan Menderes Airport and via the port of Kuşadası.

Ephesus hosted one of the seven churches of Asia, addressed in the Book of Revelation of The Bible (2:1–7), and the Gospel of John might have been written here.It is also the site of a large gladiator graveyard.

The site is large. In fact, Ephesus contains the largest collection of Roman ruins East of the Mediterranean. Only an estimated 15% has been excavated. The ruins that are visible give some idea of the city's original splendour, and the names associated with the ruins are evocative of its former life. The theater dominates the view down Harbour Street which leads to the long silted-up harbor.

The Library of Celsus, whose façade has been carefully reconstructed from all original pieces, was built ca. AD 125 by Gaius Julius Aquila in memory of his father, and once held nearly 12,000 scrolls. Designed with an exaggerated entrance — so as to enhance its perceived size, speculate many historians — the building faces east so that the reading rooms could make best use of the morning light.

A part of the site, St. John's Basilica, was built in the 6th century AD, under emperor Justinian I over the supposed site of the apostle's tomb. It is now surrounded by Selçuk.

The Temple of Artemis, one of the Seven Wonders of the World, is represented only by one inconspicuous column, revealed during an archaeological excavation by the British Museum in the 1870s. Some fragments of the frieze (which are insufficient to suggest the form of the original) and other small finds were removed – some to London and some to the Archaeological Museum, Istanbul. Other edifices excavated include:

• The Odeon - a small roofed theatre constructed by Vedius Antonius and his wife in around 150 A.D. It was a small salon for plays and concerts, seating about 1,500 people. There were 22 stairs in the theater. The upper part of the theatre was decorated with red granite pillars in the Corinthian style. The entrances were at both sides of the stage and reached by a few steps.
• The Temple of Hadrian dates from the 2nd century but underwent repairs in the 4th century and has been reerected from the surviving architectural fragments. The reliefs in the upper sections are casts, the originals being now exhibited in the Selçuk Archaeological Museum. A number of figures are depicted in the reliefs, including the emperor Theodisius I with his wife and eldest son.
• The Temple of Domitian was one of the largest temples on the city. It was erected on a pseudodipteral plan with 8 x 13 columns. The temple and its statue are some of the few remains connected with Domitian.
• The Theater - At an estimated 44,000 seating capacity, it is believed to be the largest outdoor theater in the ancient world.
• The Tomb/Fountain of Pollio - erected by a grateful city in 97 AD in honor of C. Sextilius Pollio, who constructed the Marnas aqueduct, by Offilius Proculus. It has a concave facade.

There were two agoras, one for commercial and one for state business.

Seven Sleepers

Ephesus is believed to be the city of the Seven Sleepers. The story of the Seven Sleepers, who are considered saints by Christians and Muslims, tells that they were persecuted because of their belief in God and that they slept in a cave near Ephesus for centuries.