Hamad International Airport (Doha) is the main place of entry for Qatar-bound travellers. Shuttle buses run from Qatar's only international airport to Doha every 20 minutes between 4am and midnight. Travellers must buy a Karwa Smartcard at the airport (a QR10 card is valid for two inner-city trips within 24 hours). Turquoise taxis can be flagged down; they start at QR25 from the airport. Uber (www.uber.com) is available as well.