This art gallery is a piece of art in and of itself. Architect Christoph Mäckler created the unusual exhibition space of the prestigious Frankfurt Städelschule Art Academy, located on an island in the Main river, in 2006. The Light Lab installation by famous contemporary artist Olafur Eliasson radiates through the red tower’s glass gable roof and over the Main. Emerging artists from around the world exhibit their work here—it’s one of the leading centers for experimental art.