The lead-zinc concentrate processed in Trepca, in Serbia's tense province of Kosovo, comes in through Bar, along with an array of Serbia's other essential imports including iron ore and coal.

ECONOMIST: Montenegro

In recent times, personnel met at the bunker when flash flooding struck Inverness in 2002, also after a freighter carrying 84 tonnes of diesel and 3, 300 of zinc concentrate ran aground on the Summer Isles in 2003 and in 2010 after a container holding detonators exploded in Inverness.

BBC: Bunker mentality: The Cold War bunkers still in use