Livrustkammaren, or the royal armory, is a great museum located inside the Swedish royal castle. They have some great 18th century clothes and things in their permanent exhibition, and at the moment they’re having an exhibition about shoes, many of which are from the 1700s. The rest of their stuff is fantastic as well though, one of my favourite museums.
Click this picture to go to my flickr set with photos of most of the 18th century items at Livrustkammaren.
More info can be found at their website.