Science tourism
Thomas Jefferson National Accelerator Facility – the Continuous Electron Beam Accelerator Facility, which is 1400m in length and accelerates electrons up to 6 GeV. The most powerful free-electron laser in the world has an output of over 14 kilowatts. The lab has an open house once a year that includes a tour of the accelerator tunnel and the free electron laser. No registration of visitors is required during the open house. The open house tours involve extended periods of walking, and many tour stops include stairs. Also, much of the event is outdoors.