This post on Atlas Obscura notes that worldwide there are 66 museums each dedicated to one very specific thing. And then generously, it provides links to all of them.
Most grew out of one person’s obsession, who then opened their personal treasure troves to the public. These idiosyncratic collections range from chamber pots and toilets in Prague to pencil sharpeners in Logan, Ohio and from the British Lawn Mower Museum in Southport, UK to the China Watermelon Museum in Beijing. Add to that the Museum of Carrots in Belgium and American Banjo Museum in Oklahoma City and the peculiar passions of their creators become obvious.
Talk about your special collections!