That's Yucca Flats, a US nuclear test site.
I thought it would be Laos. See http://news.bbc.co.uk/2/hi/asia-pacific/1100842.stm for others who think the same. But that's measured in number of bombs per capita. (The US dropped about 2.5 MT on Laos and 7 MT on Vietnam. The Allies dropped about 3.4 MT of bombs during WWII.)
Perhaps it's measured in total explosive power? According to http://en.wikipedia.org/wiki/Yucca_Flat there were 827 separate detonations, and if I extracted the data correctly from http://nuclearweaponarchive.org/Library/Catalog then there was no more than 72 MT at Yucca Flats.
Novaya Zemlya, site of Soviet nuclear bomb testing, "hosted 224 nuclear detonations with a total explosive energy equivalent to 265 megatons of TNT" says http://en.wikipedia.org/wiki/Novaya_Zemlya .
So I don't understand the criteria used to determine that Yucca Flats is "the most bombed place on earth."
