The best surviving example of hellenistic architecture is the city of

Hello!

I don't know your options, but a good answer is the city of Pergamon: Pergamon was a Greek city in what is today Turkey, on the western coast, and it was a capital of the Pergamon kingdom, which encompassed half of today's Turkey.

Today, the altar of Pergamon is in Berlin, in the Pergamon museum, but there are still a lot of buildings in Pergamon, which allow the visitors to have a feeling for the ancient Greek culture