Here you can find information on how to get to Ancient Olympia by car via Langadia.
Athens to Olympia via Tripoli and Langadia (280km). This route will take you through the mountains of Korinthia, through Artemisio tunnel. After the tunnel look for the sign to the right for Ancient Olympia (Αρχαία Ολυμπία) and follow the road through the mountains of Arkadia towards Vytina and Langadia. This trip is more demanding as there are more twists and turns to the road, but it is definitely a very wildlife abundant and beautiful road to travel.