Section 21.1 - Municipal corporation of another state; ownership of property necessary to beneficial use of property in other state(a) Whenever heretofore any municipal corporation of another state in the United States of America, acting in its governmental and proprietary capacity, has acquired and held real property and appurtenances attached thereto in such other state for public use and benefit, and has acquired and held real property and appurtenances attached thereto in this Commonwealth (whether in the corporate name of the municipal corporation or in the name of some person, either natural or artificial, as trustee for the municipal corporation), which was necessary to the beneficial use of the property in such other state, such acquisition and holding of real property and appurtenances attached thereto in this Commonwealth is hereby validated and confirmed and made lawful, notwithstanding the provisions of section 5 of the act, approved the twenty-sixth day of April, one thousand eight hundred fifty-five (Pamphlet Laws 328), entitled "An act relating to Corporations and to Estates held for Corporate, Religious and Charitable uses." (b) The municipal corporation may hold, use, enjoy, improve, develop, mortgage, lease and convey the real property and appurtenances attached thereto, or any part thereof, in this Commonwealth, in such manner as may be necessary for the beneficial use of the real property and appurtenances it holds in the other state, so long as it complies with the Constitution and relevant laws of this Commonwealth.1951, July 19, P.L. 1056, § 1.