Sideling Hill Tunnel is one of three original Pennsylvania Turnpike tunnels which were abandoned (this one in 1968) after two massive realignment projects. It is now surrounded by Buchanan State Forest. Sideling Hill Tunnel is long. It was the longest of the original tunnels on Pennsylvania Turnpike. Alongside the Rays Hill Tunnel, the Sideling Hill Tunnel is now part of the Pike2Bike Trail. Together, the two tunnels as well as the roadway are commonly known as the Abandoned Pennsylvania Turnpike.