The rules and regulations in this part apply to all buildings and grounds of the National Zoological Park of the Smithsonian Institution, as defined in sec. 3, 78 Stat. 366; 40 U.S.C. 193v(1)(B) , and to all persons entering in or on such buildings and grounds, hereinafter referred to as the premises.
36 C.F.R. § 520.1