This 11-story brick water tower, the tallest in Europe, must have seemed like an unlikely candidate for the sort of industrial renovation that is sweeping Germany — but punch some holes in the sides for windows, drop a restaurant on the roof, and you’ve got yourself a striking and stylish luxury hotel. Of course it doesn’t hurt to have Andrée Putman calling the shots in the interiors; her decidedly Parisian, vaguely Deco influence has transformed what could have been a cold and alien environment into a comfortable and inviting space, full of rich textures and curvaceous furniture. The circular form of the tower’s outer wall makes for some unusual and inventive floor plans, a welcome break from the box construction that seems so sensible in square hotels; but aside from that fact, it’s got everything you would expect from a top-class hotel — including wireless internet, round-the clock room service, sauna and massage, limo transfers, and perhaps most thoughtful of all, morning papers in a variety of languages. The location, in a park just outside the city center, means it’s not hemmed-in by skyscrapers or construction cranes, and lends a sort of resort feel to the hotel, a buffer from the bustle of downtown. And at the top of the tower, the chic and verdant Bar Botanik serves sophisticated drinks and upscale bites with an astonishing 360-degree view of the city.