Unique Facts

Mauna Kea, the highest point on the island of Hawaii. The inactive volcano is a modest 4,206 m (13,799 feet) above sea level, but when measured from the seabed to its summit, it is 10,200 m (33,465 feet) high – about three-quarters of a mile taller than Mount Everest. As far as mountains are concerned, the current convention is that ‘highest’ means measured from sea level to summit; ‘tallest’ means measured from the bottom of the mountain to the top. So, while Mount Everest, at 8,848 m (29,029 feet) is the highest mountain in the world, it is not the tallest. Measuring mountains is trickier than it looks. It’s easy enough to see where the top is, but where exactly is the ‘bottom’ of a mountain? For example, some argue that Mount Kilimanjaro in Tanzania – at 5,895 m (19,340 feet) – is taller than Everest because it rises straight out of the African plain, whereas Everest is merely one ofmany peaks topping the enormous base of the Himalayas, shared by the world’s next thirteen highest mo...

It’s on Mars. The giant volcano Mount Olympus – or Olympus Mons in Latin – is the highest mountain in the solar system and in the known universe. At 22 km high (14 miles) and 624 km (388 miles) across, it is almost three times the height of Mount Everest and so wide that its base would cover Arizona, or the whole of the area of the British Isles. The crater on the top is around 72 km (45 miles) wide and over 3 km (nearly 2 miles) deep, easily big enough to swallow London. Mons Olympus doesn’t conform to most people’s idea of a mountain. It is flat-topped – like a vast plateau in a sea drained of water – and its sides aren’t even steep. Their slight incline of between one and three degrees means you wouldn’t even break sweat if you climbed it. We traditionally measure mountains by their height. If we measured them by their size, it would be meaningless to isolate one mountain in a range from the rest. That being so, Mount Everest would dwarf Olympus Mons. It is part of the gigantic Hima...