The Reading Subway: Back at the turn of the century, in 1895, the Philadelphia and Reading Railroad took it's network of tracks and sidings at Pennsylvania Avenue below ground to allow for better use of the land above. What remains to this day is a cavern that housed a four track line that served various industries, including the famed Baldwin Locomotive Works. The line continued on to reach the Reading Viaduct which continued further to the Reading Terminal. Note the openings above which are vents for the Reading's steam engines as this tunnel predated electrification. The line was last used by Conrail to service the Philadelphia Inquirer.