If you have a fear of heights, please have your medication handy while watching. Introducing the 20 most dangerous bridge tops in the world that will make your hands and feet tremble.

The Sunshine Skyway Bridge, spanning Tampa Bay in Florida, has a history of collapsing due to construction errors. The accident was a result of a small contact accident being overlooked, which led to a cargo ship colliding with a pier on a stormy day with poor visibility.

A new bridge was constructed in 1987, designed to allow large ships to detect the bridge’s presence early on. An emergency alert system has been put in place in the event of an accident, providing rapid warnings to people using the bridge and the surrounding area if an accident occurs. The new bridge is much safer than the old one.