The tap water taste test
There are many things that divide the north and the south of Britain - politics, the weather - but water is probably the oddest.
You will often hear people extol the virtues of drinking water that originates from their area - whether it is the Lake District, the Pennines, the Welsh Hills or Scotland's Highlands.
Northerners protest about having to drink London tap water, but then there are Londoners who swear the city's "hard" water is superior to areas with "soft".
But is there any science behind these taste preferences?
BBC News brought together three experts to do a tap water taste test.