Service then extended further south. On May 4, 1839, the line was extended south along Bowery, Broome Street and Centre Street to City Hall at Centre Street and Park Row. Service was extended south on November 26, 1852 along Park Row to Astor House at Park Row and Broadway. In 1851, work began to convert the Murray Hill rock cut into a tunnel, and in October of that year the City Common Council ordered that a -wide planted median be installed atop the tunnel between 34th Street and 38th Street. Real estate developers who purchased adjacent lots named this section of Fourth Avenue, Park Avenue, which would later be applied to the remainder of the street. The development of the area increased once the rock cut was decked over.