The following is from http://www.ocgp.org/visit/balloon:
Soaring Above Orange County. Flights departing every Thursday-Sunday. The Great Park Balloon is the Orange County Great Park’s iconic attraction. With the ability to hold up to 25 to 30 passengers, and soar 400 feet above the surrounding landscape, it serves as a public observation deck for the Great Park’s development and offers an unmatched 360° view that spans 40 miles on a clear day….
The Great Park Balloon is one of the largest tethered helium (not hot air) balloons and the first of its kind in the United States. It is environmentally safe, non-polluting, and virtually silent.
Standing 118 feet tall with a volume of 210,000 cubic feet, the Balloon can hold up to 30 passengers in its 1,810-pound gondola. Flying at an altitude up to 400 feet, it is always tethered to the ground by a steel cable with the strength of 99,000 pounds, making it a safe and fun experience for everyone.