The tallest skyscraper west of the Mississippi River towers 73 stories over downtown Los Angeles. And the only thing better than the view from the top is the view from the glass slide on the side.

Thrill-seekers can step out of the 70th floor onto the Skyslide, suspended 1,000 feet above West Fifth Street. It stretches 45 feet to the floor below, though at that height, it surely seems much longer than that. Then riders step out of the enclosed slide onto the OUE Skyspace, the highest open-air observation deck in California.

It isn’t enough these days to have just another observation deck. It must be a destination. From rooftop rollercoasters to glass-bottomed walkways over the Grand Canyon, architects and engineers are dreaming up increasingly exciting ways to take in the view. These are just some of the stomach-churning attractions that push the bounds of engineering—and your ability to not freak out.