The town: The narrow, cobbled main street, named after Yiannis Ritsos, a Greek poet and the most famous son of Monemvasia, once served as a market. Today, it's lined with souvenir shops and cafes, many of them with vaulted ceilings, fronted by 18th-century archways. It's all extremely tasteful -- the shops selling hand-carved olive wood bowls, local honey, herbs, amygdalota (the local almond cookies) and the sweet wine, Malvasia, that's made near here. You won't find tourist tat. Alleyways run off in all directions, lined by houses painted in ochre and terracotta, with bougainvillea and gnarled olive trees providing splashes of color. A typical tour will walk you through the main street and then leave you to explore alone.
The fortress: The climb to the kastro at the top is signposted from the old town in various spots and is via narrow stone paths with a lot of steps. The stones are very slippery so wear appropriate footwear. The 20-minute ascent, scented all the way with wild herbs and flowers to a soundtrack of chirping cicadas, is hot work in summer, so take water. You'll be rewarded with sensational views down over the terracotta roofs, the ramparts and the sparkling Aegean beyond. The remains of the buildings here tell a complex history. The only way of capturing water was from the sky, so there are old storage tanks everywhere. The 12th-century church of Agia Sofia, with an impressive octagonal dome, is an engineering masterpiece, given that everything had to be carried up here on foot or by donkey. There are helpful signboards dotted around explaining what was what, in English and in Greek.
Archaeological museum: There's a small archaeological collection housed in a former mosque in the main square of the lower town, opposite the church of Elkomenos Christos. It's open Tuesday through Sunday and entrance is 2 euros. You'll see stone sculptures removed from Agia Sofia church, pottery from Asia Minor and ceramics dating back to the Byzantine era.
Visit an old taverna: Matoula is the oldest taverna in town, here since 1950 and located on the main street with a gorgeous terrace overlooking the sea. The food is traditional Greek, with decent mezes and fresh fish. Chrisovoulo, also on the main street, is fancier, with contemporary Greek cuisine and a long wine list, but you can still drop in for breakfast, or a lazy lunch if your itinerary permits.