Visitors walk on "Tiger and Turtle - Magic Mountain", a 20-metre (66 ft) high and 120 ton (109,000 kg) heavy galvanized curved steel sculpture that looks like a roller coaster, in Duisburg November 18, 2011. The new 2-million euro ($2.7 million) landmark of the Ruhr region was built on a former mining waste hill and is designed by two Hamburg artists Ulrich Gerth and Heike Mutter. The 249 steps of the 220-metre (0.22 km) long walkway are illuminated by LED at night.[Photo/Agencies]

Visitors walk on "Tiger and Turtle - Magic Mountain", a 20-metre (66 ft) high and 120 ton (109,000 kg) heavy galvanized curved steel sculpture that looks like a roller coaster, in Duisburg November 18, 2011. [Photo/Agencies]