BBC: Remnants of war,

Laos is the most bombed country on earth. The US dropped 2.4 million tonnes of bombs on it during the Vietnam War - more than the allies dropped on Germany and Japan combined in World War II.

This was quite shocking to me, since anytime you watch anything about WW2 and they talk about the allied bombing raid they always reference the Dresden Bombing raids as one of the worst in the world.

The raids saw 1,300 heavy bombers drop over 3,900 tons of high-explosive bombs and incendiary devices in four raids, destroying 13 square miles (34 km²) of the city

That is a really disturbing fact.