Where Is The Highest Mountain?

The highest mountain we know about is on Mars. It is a giant volcano known as Mount Olympus of Olympus Mons and is the highest in the solar system and the known universe.
It is 22k, high and 624km across. It is three times the height of Mount Everest and would easily cover the British Isles.
The crater on top is big enough to encompass London at around 72km and is about 3km deep.
It isn't, however much like you might imagine. The top is flat and it stands in a sea drained of water. The sides are so slight that you could easily walk up them.
Normally mountains are measured by height because to measure by the area they cover would make the distinction worthless. This is because mountains tend to be joined together in chains so it would be impossible to say where one started and another stopped.
If measurements were taken that way then Mount Everest would dwarf Olympus Mons as it is part of the huge Himalaya- Karkoram- Hindu-Kush-Parmir range, nearly 24,00km long.

The himalayas. The highest mountain peak of Himalaya is everest which lies in Nepal.