This old railway viaduct cuts the west side of Midtown Manhattan. It has been abandoned in 1980 until it was turned into an elevated park. It’s pretty short (a little less than 2 miles) but walking on it at sunset is very pleasing.
US Tour guide for 20+ years. Experienced in trekking, mountaineering and rock-climbing for large groups - up to 10+ ppl - in National Parks. DM for quote.