SnowZone, in Madrid, has 18.000 square meters of snow areas, including a 250-meters slope (over 25%, 50 meter wide) and a 100-meters long (40 meters wide), chairlifts, and other winter sports facilities.
Snowdome at Tamworth, near Birmingham with a 170m long slope and 2 smaller beginner areas - 25m and 30m long.
The first indoor ski slope, "Schneepalast" (German for snow palace) operated from 26th November 1927 to May 1928 in Vienna in an abandoned railway station, the Nordwestbahnhof. The snow was made of soda. The world's first commercial indoor ski slope operated from 1987 to 2005 at Mount Thebarton, in Adelaide, South Australia.