History of Construction > Prehistoric Era > Stone age: https://en.wikipedia.org/wiki/History_of_construction#Prehis... :

> However, it is believed that the earliest evidence of construction in the world is the 1.8 million year-old stone circle found at Olduvai Gorge representing the remains of a windbreak.

> [...] Currently, the first evidence of man-made shelter dates back to 400,000 B.C. in Terra Amata, France

Kalambo Falls is 76,000 years older according to this dating.