Syros is small enough to be manageable but spread out enough that a scooter or car makes the beaches and villages much more accessible.
On foot: Ermoupoli is entirely walkable. The hills of Ano Syros and Vrodado require some effort but are worth it. The main harbour area, Plateia Miaouli, and the market district are all within easy walking distance of each other.
Bus (KTEL): A local bus service connects Ermoupoli with Galissas, Kini, Vari, and Posidonia (Dellagrazia). The service runs several times daily in summer; frequency drops considerably in the off-season. The bus terminal is at the harbour.
Scooters and motorbikes: Rental shops are plentiful near the ferry port. A scooter opens up the whole island and is the preferred way to explore. Roads are generally good, though some villages have steep, narrow approaches.
Taxis: Available at the harbour and Plateia Miaouli. Taxi rates in the Cyclades are regulated — agree a price before you depart or insist on the meter.
Car rental: Several companies operate in Ermoupoli. A car is overkill for the town itself but useful for reaching the island's northern prehistoric sites.