Your day starts seventy metres from the sand, in clear water over a seabed worth a mask. In the evening, dinner is at a taverna on the water, a few steps from your door.
Ermoupoli is the Cyclades nobody expects: a nineteenth-century shipping capital of marble squares and neoclassical mansions. Walk from the Town Hall on Miaouli Square to the Apollo Theatre, then down to Vaporia, where captains' mansions rise straight from the sea beneath the blue dome of Agios Nikolaos.
Then climb to Ano Syros, the medieval Catholic town on the hill, where whitewashed lanes wind up to the Cathedral of St George and the whole Aegean opens out below. Orthodox and Catholic neighbours have shared this island for centuries, which is why it still feels lived in rather than staged. And don't leave without a box of Syros loukoumi.