Which mountain range separates Europe and Asia?

The Urals, and the boundary they mark is a convention rather than a discovery. Europe is not a separate landmass by any physical test - it is the western end of Asia - so where the line sits has always been a decision. The Urals became the answer largely because a Swedish officer in Russian service, Philip Johan von Strahlenberg, proposed them in 1730 and it suited Peter the Great's argument that Russia was a European power with an Asian province rather than an Asian empire.

They are also very old and correspondingly modest. Formed around 250 to 300 million years ago when two continents collided, they have been eroding ever since and the highest point is under 1,900 metres - a range that has been worn down for longer than the Atlantic has existed.

The mineral wealth is the reason they mattered. Iron, copper, gold, platinum and gemstones made the Urals the industrial base of imperial Russia, and in 1941 entire factories were dismantled and moved east behind them, out of German reach, and restarted within months - a feat of logistics that is a substantial part of why the Soviet Union was able to keep fighting.