Groningen's Eelde Airport is 15km south of the city centre, along the A28 highway. Taxis charge a fixed fee of €30 for the 15-minute ride to the city centre (€55 if you also prebook a return trip); it's a good idea to call ahead. Hertz and Europcar offer car rental. Bus N°2 (ticket €5, €3,26 using an OV-Chipcard) departs every 30 minutes (every hour on Sundays) and takes 40 minutes to reach the central station, after which it continues to Grote Markt square. The Airportliner express bus meets Ryanair arrivals and charges €4 for the 20-minute ride to Central Station and the Martini Hotel (in the city centre at Gedempte Zuiderdiep 8). If you're arriving at Amsterdam Schiphol Airport, you can take the train directly from Schiphol's train station to Groningen via either Lelystad or Zwolle. There's no need to go to Amsterdam central station first, and many Groningers would say that's a good thing.