You can easily tour the region in either a clockwise or counterclockwise direction. Whichever approach you choose, at some point you'll probably head into the center of the Peloponnese, either to see the Byzantine ghost town of Mistra outside ancient Sparta, or to take in some of the mountain villages of Arcadia and the Temple of Vassae dedicated to Apollo. Here's one suggested itinerary based on the assumption that you have your own car and are setting out from Athens. If you're traveling by public transportation, you'd be wise to double the time allowed. Even if you do have a car, don't let yourself be deceived by the short distances between what you want to see in the Peloponnese. You'll be astonished at how long even a short drive on a winding mountain road can take -- especially when you have to stop repeatedly to let flocks of goats cross that road!
If you have 2 days, head from Athens to Corinth, have a look at the canal, and visit the sprawling ancient site with its impressive temple as well as Acrocorinth, the sugarloaf mountain that looms over the plain of Corinth. Head on to Mycenae to see the citadel and chamber tombs before ending up for the night in Nafplion, which just about everyone calls oraia (beautiful); refresh yourself with a swim at the public bathing beach, some window-shopping along Nafplion's pedestrianized streets, and dinner. In the morning, explore Nafplion's museums and monuments and drive over to Epidaurus to see the famous theater before heading back along the coast to Athens.
If you have a few more days to spend here, you can head from Nafplion to Olympia, taking in some of the Arcadian mountain villages, including Andritsena, with the Temple of Vassae. Then you can head back to Athens along the Gulf of Corinth, which offers lots of chances for lunch and a swim at seaside resorts such as Xylokastro. There's still lots more to see in the Peloponnese -- so let's hope that you have at least a week to spend here and can take in Sparta and Byzantine Mistra and the fortress (and chic hotels) of Monemvassia and the tower house villages of the Mani. And remember: If you are heading from the Peloponnese into Central Greece, the Rio-AntiRio suspension bridge which opened in 2004 makes a journey from, for example, Olympia to Delphi, very easy.
Many of the best-known ancient sites in the Peloponnese, including Olympia, Corinth, and Epidauros, were threatened by the forest fires that raged through Greece in the summer of 2007. The ancient sites were undamaged, but as you travel, you may see once green hillsides with stands of blackened tree trunks left behind by the fires.
Museum Hours Update
If you visit Greece during the summer, check to see when sites and museums are open. According to the tourist office, they should be open from 8am to 7:30pm, but some may close earlier in the day or even be closed 1 day a week.