300 Main Street Marketplace is a shopping destination located in Nashua, NH. As a Community Center, it occupies a prime spot at Main St. & Otterson Sts.. Since opening in 1963, 300 Main Street Marketplace has been refreshed with a renovation completed in 2003. Shoppers can explore 275,000 sqft. of retail floor space featuring approximately 35 stores. Ample parking is provided with 1,259 spaces available.