While little remains to attest to Spartan power and might, residents of the Byzantine capital just to the west left behind a treasure trove of architectural splendors. A visit to Sparta requires a fertile imagination; in Mystras all you need is a good pair of walking shoes and some water as you scramble amid the copious remnants of the last days of the Byzantine Empire.
In spring Mystras is resplendent with wildflowers and butterflies, but it can be oppressively hot in summer, so get an early start to avoid exploring the site in the midday sun. That said, it's easy to spend half a day here, so wear sunscreen, a hat, and sturdy shoes for traction on slippery rocks. If pushed for time, you can cut your visit in half by parking at the upper entrance, from where it's only a 10-minute ascent to the castle atop the hill. Do watch out for the occasional snake on the way up.