Cities are hereby empowered: to acquire by purchase, gift, lease, sublease, or otherwise hold and take over such lands as the city council may deem necessary within or without the corporate limits whether within or without the county in which said city is located; do all things necessary in cooperation with the United States government in adapting any such lands so acquired to national defense purposes; and for the purpose of maintaining aviation facilities, to lease for aviation purposes, or any purposes connected therewith and incident thereto, all or any part of such land or lands, under such regulations and upon such terms and conditions as shall be established by the city council or otherwise established by law; to construct, operate and maintain, consistent with such regulations as may now exist or may hereafter be established by law, hangars, buildings and equipment necessary or convenient to the maintenance and operation of aviation facilities; to survey, plat, map, grade, ornament and otherwise improve such land, appurtenances, approaches, and avenues leading to or adjacent thereto; to provide for all costs and expenses incident or necessary to the exercise of the foregoing powers or the attainment of the foregoing objects out of the general fund of said city or in its discretion by special levy, in an amount not to exceed six hundredths percent (.06%) of the market value for assessment purposes in any one (1) year on all the taxable property within such city or by the issuance of bonds as provided by sections 50-1001 through 50-1042, Idaho Code.