This takes guts to watch, never mind to take part in.
A vertigo-inducing video emerged overnight of two men playing at the top of the Burj Khalifa in Dubai, the world's tallest building.
The men, who appear to be maintenance crew, filmed themselves at the peak of the 2,722-foot skyscraper, which dominates the Middle Eastern city-state's skyline.
At one point one of the men, wearing a safety harness, leans back and lets go of the building's frame, with a sheer drop to the desert floor beneath him.
It is not known who uploaded the video, but it is likely to be frowned upon by authorities in the city who deplore anything that could be construed as bad publicity.
Similar videos, often of Russian youths climbing unharnessed to the tops of massive radio structures, have swept the Internet in the last two years.