The legislative body of all Cities is empowered to zone "for the purpose of promoting health, safety, morals or the general welfare of the community." "Such regulations shall be . . . designed to lessen congestion in the streets; to secure safety from fire, panic and other dangers; to promote health and general welfare; to provide adequate light and air; to prevent the overcrowding of land; to avoid undue concentration of population; to preserve features of historical significance; to facilitate the adequate provision of transportation, water, sewerage, schools, parks and other public requirements. Such regulations shall be made with. . .a view to conserving the value of buildings and encouraging the most appropriate use of land throughout such municipality."