If you're going to Costa Navarino, I highly recommend stopping at Ancient Messene on the way - it will take you about 20 minutes off the route and is one of the most amazing, and undervisited, ancient sites in Greece. The site goes on, and on, and on - each time you go down one level, you discover more to see until you hit the ancient stadium.

From the resort - Nestor's Palace is a quick 15 minute drive. Methoni is about 40 minutes away, but the castle is well worth it. It's also a nice day trip along the coast up to Ancient Olympia.