In 2003, when a tornado struck the Kinzua Viaduct, once the longest and tallest railroad bridge in the world, the engineers turned a disaster into an opportunity and built a pedestrian skywalk with a glass floor on the remaining support towers. Kinzua Bridge State Park in northern Pennsylvania offers you a tour of the American rich railroad past as well as breathtaking views of the surrounding mountains.

It took less than a year to build the original viaduct back in 1882. Think about it for a second: 1882 meant no heavy cranes, not even safety nets. Yet it took them that little time to build a structure that not only provided an immediate economic benefit but has been evoking awe for more than 100 years.

301 ft / 91 m high and 2,053 ft / 625 m long, made from iron, the viaduct allowed to transport of coal, lumber and oil from McKean County which was vital to the local economy. In 1900, the iron was replaced with steel to ensure that heavier trains could use the bridge.

No more freight trains could make use of the bridge after 1959 when the entire structure with the adjacent area was designated a state park. However, the operations slowly continued into 2002 until the bridge was deemed too dangerous to carry vintage trains with park visitors.

Little did the park's authorities know that a year after, in 2003, a tornado would strike the area and take almost the entire structure down.

If you have a good imagination, you can try to picture the whole apocalyptic scene with falling towers, the roar of bending steel, flying debris, and over 100 miles/hour wind.

Eleven damaged towers remain scattered on the valley floor.

But instead of clearing the debris, the park's authorities decided to create an attraction like no other: the six original towers were restored to support a skywalk that takes visitors to an observation deck with a 360-degree view of the Kinzua Creek Valley and surrounding mountains.

In addition, two more overlooks are offering perfect views of the bridge and a short but steep trail that takes you to the bottom of the valley next to the debris field.