If you're planning to overnight by the airport, you might as well do it in style. This 370-room cubist-meets-modernist structure looks like a concrete cruise ship, with bare-walled, uberswish rooms (the deluxe doubles have beds facing a private balcony and quirky triangular tubs), and a gorgeous outdoor pool (₩55,000 per person) beside the West Sea.
It's a 15-minute ride on the hotel shuttle bus to the airport, or you can take the free Maglev which stops a few minutes' walk away from the hotel.