Here are pictures of an insulator adventure that yielded nothing, but was a great explore non the less. When the turnpike opened in 1940, it consisted of 7 tunnels going through the mountains of central PA. All of these tunnels were a single tube with two lanes, and as the road became busier, bottlenecks developed around the tunnels. In the 60s, bypasses were built around three of the old tunnels, and the others had a second tube added. This particular tunnel at Sidling Hill is over a mile long and was abandoned in 1968. This section of road has become a bicycle trail in recent times and is a tourist attraction.