Conversation so far:
what is the tallest building in the northern hemisphere
Burj Khalifa is the tallest building in the Northern Hemisphere.
what is the tallest building in the southern hemisphere
Q1 is the tallest building in the Southern Hemisphere 2018.
what is the tallest building in the eastern hemisphere
Burj Khalifa is the tallest building in the Eastern Hemisphere.
what is the tallest building in the western hemisphere
One World Trade Center is the tallest building in the Western Hemisphere.

Question: in Africa
Self-contained rewrite: what is the tallest building in Africa