BASE jumping is parachuting off a fixed platform. The name comes from Buildings, Antennae, Spans and Earth, indicating jumping off an edifice, ancillary installations, bridges and natural formations.

Contrary to skydiving (parachuting off an aeroplane), BASE jumping is considered an insanely dangerous activity, as 1 in 200 jumps results in serious injury and 1 in 2,600 in death. As the jump heights are far lower than in skydiving, there is no freefall, there is very little leeway for errors, any canopy malfunctions may be fatal as there is not enough height for a reserve canopy, and sudden gusts of wind may mean troubles on deployment of the canopy and steering. Also the landing is often hazardous.

BASE jumping got famous after the release of the James Bond 007 movie "The Spy who Loved Me" (starred by Roger Moore), as James Bond performs a parachute jump off the cliff at the beginning of the movie. He uses a bell canopy with Union Jack on it.

BASE jumping is considered illegal in many countries, as it often involves trespassing of private property.

More Info: en.wikipedia.org