Visit the world's first light art museum

In the catacombs of the Linden Brewery, which was closed in 1979, a unique museum has been created. In the passageways and storage rooms, artists have curated their installations specifically for the site. A highlight is this "Tunnel of Tears" by the artist Keith Sonnier, which is made up of red and blue fluorescent tubes. The interplay deceives the eye and the colors take on a new perspective.

The underground museum covers several thousand square meters. The rooms hardly resemble the usual bright white surfaces of typical museums. Down here the walls are damp and there is no heating. But the light installations, like this one called "I (in Dialogue)" by Jan von Munster, bring light into the darkness of the old brewery's basement. Visits are only possible with the assistance of a guide.

James Turrell is represented in the exhibition with two major installations. He made a special trip to Unna from Arizona in order to construct his works. With "Floater 99" the contours of the architecture seem to dissolve in the diffuse icy blue and magenta hues. The visitor merges into the light through complete immersion of color.

This installation by light art pioneer James Turrell is reminiscent of a walk-in camera obscura. The work consists of two parts. In the first room light passes through a small lens located on the floor and the most miniscule movements - such as the wings of birds - are projected. In the overlying "Skypace," artificial and natural lights fuse to create an organic yet profound spectacle.

François Morellet has chosen a former refrigerator to exhibit his installation "No and Neon." He has mounted nine neon light tubes in a variation of angles. The tubes react to movement, projecting different shades of light according to the angle.

Rebecca Horn is one of Germany's most celebrated artists. She chose to set her installation "Lotus Shadow" in the vault, which is below groundwater level. Like sea plants, the copper lamps entangle their bright flower heads amidst one another. They project small islands of light onto the damp walls to a soundtrack resembling a whale song.

Christian Boltanski plays on our fear of the dark. Witches or devil-like figures dangle from a scaffold and are illuminated in a way that projects their creepy shadow-dancing upon the wall. Boltanski draws on his own childhood memories. His Jewish father died during the Holocaust, and he also alludes to the persecution of witches in the Middle Ages - for which evidence can be found in Unna.

Once used for brewing beer, sound artist Christina Kubisch has brought back the sound of the distant past by mounting 172 speakers to the bottom of the stone fermenting vats. The light dissolves from the ground and you start to feel as though you are floating, while dull sounds blare out of the speakers.

Experimentation with natural phenomena is the specialty of Olafur Eliasson. The Danish artist is notorious for his convergence of art and science. As the visitor moves onto the catwalk light, resembling water, it rushes down with a loud splash. Powerful strobes seem to slow the fall of the water - each drop having a singular effect.

The radio of light and time is the concern of Austrian artist Brigitte Kowanz. "The speed of light, 11.5m" is illuminated above the entrance of the former brewery. It is made up of 19 neon numbers underlined by a neon row consisting of three elements. It is one of the few installations situated above ground.