In the southern part of the city is the socially diversified community of Río Piedras. Founded in the mid-1850s, Río Piedras was a separate town which hosted sugar cane plantations and the estates of some of San Juan's wealthiest inhabitants (as well as their working class staff). The Spanish colonial governors also had their summer home there on land which eventually gave way to the main campus of the University of Puerto Rico. In 1951 the municipalities of San Juan and Río Piedras were merged to redefine San Juan's current city limits. Today Río Piedras comprises the largest area of the municipality of San Juan. and is home to the "Plaza del Mercado" (Río Piedras Marketplace), the main campus and the Medical Sciences campus of the University of Puerto Rico and the San Juan Botanical Garden.