In this spectacular activity centre, those seeking adventure can try surfing, flying and other activities in the Arena’s more than 15,000 square metres of space. At the indoor surfing pool, which has a wave 1.40 metres high, a solar simulator ensures that the "sun's rays" are clearly visible on the adjacent wooden wall. In the 30-metre-high wind tunnel, LFO lenses disappear completely into the structured ceiling. The light shines out of a hole that is only eight millimetres in diameter