There are two airports in the Western Peloponnese, Araxos and Kalamata, though flights here are limited. The nearest international hub is Athens, with direct flights from most major UK and European cities, as well as the USA, Asia and the Middle East. From Athens, you can reach the Western coast of the Peloponnese in 2.5 hours by car (the journey to both Patras, in the north, and Kalamata, in the South, is more or less equidistant).
Driving is a delight in the laid-back Peloponnese, where the roads are quiet, and the fuel is cheap. There’s signposting in English, and spectacular views to boot, but always allow for plenty of time; steep gradients and hairpin bends warrant caution, if not the occasional herd of wandering goats.