Peru is a city in LaSalle County, Illinois, United States. The population was 10,295 at the 2010 census. It is part of the Ottawa - Streator Micropolitan Statistical Area. Peru and its twin city, LaSalle, make up the core of Illinois Valley.GeographyPeru is located at . According to the 2010 census, Peru has a total area of 9.068sqmi, of which 8.96sqmi is land and 0.108sqmi is water.Located on the Illinois River, Peru lies 3mi west of the intersection of two major interstate highways: Interstate 39 and Interstate 80. The city is also the western terminus of the historic Illinois and Michigan Canal. Before the Illinois Waterway was constructed, the Illinois River was navigable only up to Peru. Starved Rock State Park, a regional tourist attraction, is located 5mi south-east of the community. Peru has a twin city on its eastern edge, LaSalle.DemographicsAs of the census of 2000, there were 9,835 people, 4,143 households, and 2,672 families residing in the city. The population density was 1,655.5 people per square mile (639.3/km²). There were 4,413 housing units at an average density of 742.8 per square mile (286.8/km²). The racial makeup of the city was 96.47% White, 0.32% African American, 0.18% Native American, 1.11% Asian, 0.01% Pacific Islander, 1.16% from other races, and 0.75% from two or more races. Hispanic or Latino of any race were 4.08% of the population.