Built for the 1964 World’s Fair at a cost of $672,000 (about $5.3 million in 2017), the Panorama of New York City at the Queens Museum is  the world’s largest architectural model of a city. It includes about 895,000 miniature buildings, streets, parks and bridges, made mostly of wood and plastic; at a scale of 1 inch = 100 feet, the 321 square miles of the city’s five boroughs take up 9,335 square feet and the 1,500-foot Empire State Building is 15 inches tall.

Sources here, here, here, and here.