İsa Bey Camii
Lovely and evocative, this is one of the most ancient mosques in western Türkiye, dating from 1375. The jumble of architectural styles suggests a transition between Seljuk and Ottoman design: like later-day Ottoman mosques, this one has a large courtyard, though the interior is plain (in the 19th century, it doubled as a kervansaray). The structure is built out of spolia, or "borrowed" stone: marble blocks with Latin inscriptions, Corinthian columns, black-granite columns from the baths at Ephesus, and pieces from the altar of the Temple of Artemis. Don't miss it if you're visiting the St. John Basilica—it's a 3-minute walk downhill as you turn right out of the gate.
