The first hotel from the Dutch group citizenM opens today at Schiphol Airport in Amsterdam. Designed by local architectural firm Concrete — who did the Van Gogh Museum and Mercedes Benz building in Stuttgart — the six-story building is a minimalist box of metal and glass. Rooms feature floor-to-ceiling windows and touch-screen mood pads that let visitors personalize the lighting, temperature and music. Preferences are saved on key cards, which automatically adjust the settings when guests arrive. The citizenM is the latest example in a growing number of upscale airport hotels. Yet the next outpost (one in more than a dozen planned throughout Europe) will open next year in the heart of Amsterdam.