Lego bricks were invented by Danish carpenter Ole Kirk Kristiansen in 1958. Employees at the Lego factory in Billund, Denmark started to put Lego models outside. These models were instantly very popular with visitors to the factory so it was decided to turn them into a tourist attraction - this became the first ever LEGOLAND. The first Legoland Discovery Center was opened in Berlin in 2007, and since then a total of 12 LEGOLAND® Discovery Centers have been opened. LEGOLAND® Discovery Center Chicago opened in 2008 and was the first LEGOLAND Discovery Center in North America. LEGOLAND Discovery Centers are small indoor attractions, whereas the LEGOLAND parks are large outdoor theme parks with roller coasters.