In a soaring glass tower overlooking the inner city from across the Danube canal, this hotel is about as abstract as it gets in Vienna. Slightly aslant, the tower's soaring glass walls embrace the outdoors. Jean Nouvel designed the structure and every detail fits stylishly into the sleek exterior. Video installations by Swiss artist Pipilotti Rist flash color from soaring windows on the 18th floor, creating a light show that can be viewed both from the street and from within. The rooms come in gray, black, or white, and shadows of poems by students from the Vienna School of Fine Arts decorate the walls at intervals. Nouvel's curvy furnishings add to the artsy vibe, as do Asian-style sliding screens to the bathrooms. The serene So Spa has a whirlpool and steam bath and offers Carita and Cinque Mondes treatments. The hotel boasts an unrivaled view from the rooftop Le Loft bar and restaurant, while the gourmet French cuisine and service have a hard time living up to the view, but it's certainly a nice spot to sip from the notable list of Austrian wines on offer. The buffet breakfast is exquisite, though not included in the price.