The governing body of such city may lease to the board of education for a period not exceeding twenty years, on terms and charges to be fixed by such lease, all or any part of such military memorial park, recreation or athletic field as may be adjacent to and adjoining any public school property in said city, for the purpose of providing adequate facilities for athletics, amusements, and recreational activities of the schools, and permit and authorize the board of education to charge and collect admission fees for school activities, and the governing body may permit the board of education to erect a stadium and such buildings and fixtures and fences thereon as may be deemed necessary to carry out such purposes: Provided, however, That nothing in this act shall be construed to interfere with the use of such military memorial park, recreation or athletic field by the public, civic, religious, charitable and war veterans organizations at any and all times, save and except when in actual use by the schools: And provided further, That the governing body of such city may from time to time issue permits for the use of said military memorial park, recreation or athletic field and fix the terms and charges therefor and shall permit the civic, religious, charitable and war veterans organizations to charge and collect admission fees for their respective activities.