Soaring almost 400 meters above the rainforests of São Tomé island in Africa, this tower-like natural formation called Pico Cão Grande is considered one of the most challenging climbs in Africa. The near-vertical walls, formed from a volcanic plug, offer little in the way of easy routes. The first recorded successful ascent, by a Japanese team, only happened in 1991, highlighting the mountain's formidable reputation.

Besides the near-vertical walls, there are some other, rather scary, reasons why climbing Pico Cão Grande is so difficult
Credit to the owner