Section 3a. Acquisition of lands by state and subdivisions; sale of excess

The state or any of its counties, cities, towns or villages may acquire by gift, dedication, purchase, or condemnation lands for establishing, laying out, widening, enlarging, extending, and maintaining memorial grounds, streets, highways, squares, parkways, boulevards, parks, playgrounds, sites for public buildings, and reservations in and about and along and leading to any or all of the same; and after the establishment, layout, and completion of such improvements, may convey any such real estate thus acquired and not necessary for such improvements, with reservations concerning the future use and occupation of such real estate, so as to protect such public works and improvements, and their environs, and to preserve the view, appearance, light, air, and usefulness of such public works. If the governing body of a county, city, town or village elects to accept a gift or dedication of land made on condition that the land be devoted to a special purpose and the condition subsequently becomes impossible or impracticable, such governing body may by resolution or ordinance enacted by a two-thirds vote of its members elect either to grant the land back to the donor or dedicator or his heirs or accept from the donor or dedicator or his heirs a grant relieving the county, city, town or village of the condition; however, if the donor or dedicator or his heirs are unknown or cannot be found, such resolution or ordinance may provide for the commencement of proceedings in the manner and in the courts as the legislature shall designate for the purpose of relieving the county, city, town or village from the condition of the gift or dedication.