The Hanford B-Reactor National Historic Landmark Tours are offered Monday through Saturday, from April through September. During the tour season the visitor center is closed on Sundays and during the off season, the visitor center is closed Friday through Sunday. Visitors can register for tours by online, phone, or in person. The free, guided tours last approximately 4 hours, including travel to and from the B-Reactor on a Department of Energy (DOE) sponsored bus. DOE will also offer tours of the pre-Manhattan Project facilities during the same timeframe.