This isn't really surviving, but maybe you could have some kind of time warp or something that makes them transported to and appear in our modern world.
Even if they had somehow survived, with the passage of time the language and culture and politics and even the city states themselves would have evolved into something different than they were some 2500 to 3000 years ago.
To have them survive absolutely intact as they were in The Golden Age or the Helenistic age is not possible. The passage of time would have changed everything and with the passage of that many years they would have changed a lot.