By train is the obvious choice. Direct services run from Hamburg, Cologne, and other major German cities to Westerland (Sylt), the island's terminus. The crossing over the Hindenburgdamm causeway is part of the journey.
Drivers must load their cars onto the Autozug shuttle train at Niebüll on the mainland — no road crosses to the island. Book online in advance in summer; queues at peak times can mean a wait of several hours. The crossing takes about 35 minutes.
Sylt Airport (GWT), just east of Westerland, has seasonal connections to Munich, Frankfurt, Cologne, Vienna, and Zurich. Schedules are limited and prices high.
A car-ferry runs from Rømø in Denmark to List on summer schedules — useful for combining the trip with a Denmark visit.