Wear shoes with grip on the cobblestones, not flip-flops
Flip-flops on the cobblestones are a mistake. I made it for my first month and I paid for it. The stones are uneven, and in the rainy season, from June to October, they get slick near the plaza. Wear closed shoes or sandals with a strap and a real sole. You will walk more than you expect, because golf carts are slow and taxis are for the long ride. Keep the flip-flops for the sand.