As any Shetland Islander will tell you, they are as much Scandinavian as Scottish (listen to their accents!), and this is reflected in Up Helly Aa, a fire festival held each year where brawny men parade through the streets in horned and winged helmets and pretty much anything that will catch alight is set alight. It's not a particularly old tradition (it started in 1880) but, by Odin, they really go for it.
It's tonight, by the way, so I should probably have mentioned it a few days ago as, even for Scottish readers, Shetland may be quite a trek. Sorry.
