(I'm posting 2 at once here, so scroll down for the first one. Or don't - it doesn't much matter).
The conference over, I had Saturday and most of Sunday to explore. One of the people I work with insisted that I buy a Stockholm card, which gives free entrance to heaps of museums and free transport. I chose not to, because it was really nice weather and the central islands are easy to walk around. There are a lot of museums, but some of them sound a bit second-rate. I went to 3: the Historiska, the Royal Armouries, and the Vasa. All three were great.
The Historiska is not big, but it has a good Viking section. They have a room full of treasure called the Goldrummet (containing 50kg of gold artifacts). One of the treasure hoards was found when a boulder was dynamited, sending the silverware that was hidden inside flying in all directions.
The Royal Armouries is attached to the Royal Palace:
It features possessions of the royal family, including (fascinatingly but morbidly), the blood-stained clothing that the various members of the royal family were wearing when they were assassinated. One was shot in the back at a masked ball, another was shot in battle, another by a sniper while inspecting a trench. If you work in personal insurance and the Swedish Royal family knock on the door, tell them you're busy.
It also had the royal carriages, and a collection of the royal sleds. That's how you know a country is cold:
The third museum was the Vasa. You may not've heard of this one, but it's nothing short of stunning. The Vasa is a warship that the Swedish built in 1628. There wasn't enough balast in the hull for 2 decks of cannons, and it sunk into the harbour on its maiden voyage. The woodworms that would normally destroy a ship like this do not live in the Baltic sea, so it lay there undisturbed.
It was rediscovered in the 1960s, and raised. It was sound enough that when they raised it and pumped the water out, it floated on its own. Add it to your list of things to see. Remarkable.