FORT LEE, N.Y. — SJP Properties has broken ground on two 47-story apartment towers in Fort Lee, decades after the site near George Washington Bridge was first cleared for development. SJP is working in partnership with Prudential Real Estate Investors and Northwestern Mutual Life Insurance Co. on the $500 million project. The redevelopment, known as The Modern, will feature 900 luxury apartments and a public park with a 7,000-square-foot restaurant. SJP will also develop a 13,000-square-foot building to be donated to the Borough of Fort Lee, which will house a theater and museum. The buildings will be located at 100 and 800 Park Ave. and residents should be able to move in during the summer of 2014. PNC Bank and Wells Fargo are providing the construction financing.