Ancient Site
Ancient Agora of Athens
AYN-shunt AG-uh-ruh of ATH-inz · Modern Athens, Attica, Greece · 37.9750° N, 23.7229° E
The principal civic and commercial marketplace of ancient Athens, northwest of the Acropolis, filled by the 1st century CE with temples, altars, statues, and colonnaded stoas. Acts 17:17 records that Paul "reasoned in the synagogue with the Jews and the God-fearing Greeks, as well as in the marketplace day by day with those who happened to be there" — the daily philosophical and religious debate that eventually led the Stoic and Epicurean philosophers to bring him before the Areopagus.
Archaeology
Systematically excavated by the American School of Classical Studies at Athens beginning in 1931; the reconstructed 2nd-century-BCE Stoa of Attalos now serves as the Ancient Agora Museum. By Paul's time the square had become an open-air museum of altars and statues collected over centuries — the same religious density that likely included the "altar to an unknown god" he references in his Areopagus speech (Acts 17:23), though that specific altar has never been recovered archaeologically.

On a modern map
Further reading
More sites
Capstone Bible is a free interactive study app — a map of every place in this library, a zoomable timeline of biblical and church history, the Bible text with every name in it linked to its article, reading plans and personal notes.
Open Capstone Bible