The so-called “Temple of Hadrian” at Ephesus is located on the street connecting the library of Celsus with the upper part of the city which is commonly known as the Street of the Curetes. Ephesus was the capital of the province, and the thriving Ionian city had taken the place of Pergamum as the seat of the Roman government during the rule of Augustus. The façade of the temple is characterized by a Corinthian dystilos in antis. The two central columns are set between two pillars, located at the corners. The colonnade is topped by a characteristic curved arch, the Syrian Gable. Its main characteristic is that the architrave and frieze turn in a central arch, which supports the triangular pediment. The top of the arch is decorated with a relief depicting the bust of the local city goddess, or Tychê. The head of the goddess is topped by the turreted crown. The inner frieze, which can be seen through the pediment's archway, depicts the head of Medusa, surrounded by acanthus leaves. Four reliefs decorating the frieze of the pronaos, portray the legendary foundation of Ephesus. The first frieze depicts Androclus killing a board with his spear. Androclus was the son of Codrus, the king of Athens. Once sent by his father to conquer Ionia, he defeated and chased away the local populations of the Leleges and the Carians, who dwelt in the area where Ephesus was founded. According to an oracle, Androclus founded the city in a spot which was revealed by two animals, a fish and a board. Hence the depiction of the hunt also reported by Pausanias, Description of Greece VII.2.7-9; Athenaeus, Deipnosophistae VIII.361 c-e. The other two friezes depict the procession of Dionysus, and an Amazonomachy. The topic of the fourth frieze is unclear, but once more it ought to be related to Androclus. The hero is depicted together with Heracles, as well as Apollo and Athena. The plan of the temple is quite simple, and it consists of the pronaos, onto which opens the cultic cella. It seems that the Temple of Hadrian was still in use in Late Antiquity. A central location in the city, it seems to have lodged statues of the four Tetrarchs between 293 and 305 CE, namely Diocletian, Maximian, Constantius Chlorus, and Galerius. Only the monumental inscribed pediments have been discovered, while the statues are still lacking.

The imperial cult in Ephesus officially began under Augustus when the ruler authorised the Romans to dedicate a temple to both Julius Caesar and himself, while the Greeks built one in Pergamum (Cassius Dio, Roman History LI.20.7-9). Smyrna was also granted the right under Tiberius (