The Authority may set up and operate such activities within park areas as it deems desirable in the public interest, or if a majority of the members of the Board so vote, it may lease to private individuals concessions within the area in conformity with rules and regulations prescribed by the Board. All leases granted within the park areas shall contain a cancellation clause in favor of the Authority, whereby the term may be cancelled, in the public interest, upon the violation of any rule or regulation by the lessee. This rule shall apply also to all persons making temporary use of any of the facilities who, in case of improper conduct, may be ejected from the premises.