BASE jumping is an extreme sport that involves jumping from fixed objects, such as buildings, bridges, and cliffs, using a parachute to safely return to the ground. The acronym BASE stands for Building, Antenna, Span (bridges), and Earth (cliffs) . Participants exit from a fixed object, and after an optional freefall delay, deploy a parachute to slow their descent and land. BASE jumping is considered an extreme sport because it is extremely dangerous, and to date, over 300 BASE jumpers have died as a result of accidents that occurred during BASE jump attempts. Regular skydiving is much safer than BASE jumping. A popular form of BASE jumping is wingsuit BASE jumping, where jumpers wear a special suit that allows them to glide through the air. BASE jumping can be illegal in certain areas due to the potential risk for traffic congestion or pedestrian injury in heavily populated areas, and an unnecessary stressor for National Park visitors and first responders.