Geography

Rivers, lakes and the measurements behind 'longest' and 'largest'.

• 
  Quiz: How Much Does a Square Metre Cost in 10 Big Cities?

  Ten questions on home prices per square metre in Paris, Berlin, Madrid, Lisbon, Vienna, Stockholm, Warsaw, Hong Kong and more, each answer dated and checked against official statistics.

• 
  The Largest Lakes in the World, by Area, Depth and Volume

  The Caspian Sea, Lake Superior, Lake Victoria and Baikal: the world's largest lakes ranked three ways, with the definitional arguments that change the answer.

• 
  The Longest Rivers in Africa: Top 10 and Why Lengths Vary

  The Nile, Congo, Niger, Zambezi and the rest of Africa's ten longest rivers, with lengths, outlets and countries, plus why published lengths disagree.

• 
  The Seven Summits: The Highest Mountain on Each Continent

  Everest, Aconcagua, Denali, Kilimanjaro, Elbrus, Vinson and Puncak Jaya or Kosciuszko: the highest peak on each continent, their surveyed heights, and why there are two rival lists.