The Husafell stone (aka Africa stone) is a fairly flat, almost triangular stone weighing around 175kg (385lb)  which has been used in Strongman events for a number of years.
In the World’s Strongest Man competitions the Husafell stone is lifted from a waist-high platform to chest height, and carried for distance. Once the stone is dropped, or in the case of the competitor moving outside their designated lane, the carry is terminated and the distance measured . During the years in which this event took place on African soil, the stone was known as the Africa stone (and shaped accordingly).
A spot of history : This stone originally formed the basis of a challenge in Iceland’s Husafell Valley (hence the name). The task was to lift and carry the Kviahellan approximately 50 meters around Sira Snorri Bjornsson‘s goat pen – quite a feat. Those who were able to achieve this are known simply as ‘Fullsterker‘ (fully strong). Fantastic.
1. World’s Strongest Man
The African Stone
World’s Strongest Man
Video 3mb, .mov] of Dr. William Crawford achieving fullsterker (full strength) status by hoisting the Husafell Stone and taking it for a walk around the goat track (approx. 50m).
To Lift a Heavy Stone[1.8mb, .pdf]
A detailed look at the techniques involved in heavy stone lifting.