When people think of volcanoes in Europe, the first one that comes to everyone's mind is probably the one that destroyed Pompeii, mount Vesuvius. The risk of that is probably negligable compared to that of it's close neighbour, Campi Flegrei. It's not nearly as large as the Yellowstone hotspot, but large enough to cause global cooling if it blows. A large part of Naples lies inside its caldera, in which around half a million people live. It is a very active spot and volcanologists say it shows signs of "reawakening" and may be nearing a critical pressure point. If it does, its effects will be felt all over Europe and Africa and probably all over the planet.
Another one is Danau Toba, a large lake in Sumatra, Indonesia that is actually the caldera of super volcano. The island Pulau Samosir was formed because the bottom of the 62 by 19 miles lake has risen almost 1,480 ft since its formation. It has an even bigger magma chamber than Yellowstone has and its eruption would probaly cause a global catastrophy. Luckily there are no signs it is about to become more active and dangerous.
http://www.iflscience.com/environment/the-toba-supervolcano-has-a-bigger-underground-magma-chamber-than-yellowstone/
helps a little bit.
