The Art Gallery Problem

The wonderful book, Proofs from THE BOOK,

http://www.amazon.com/Proofs-BOOK-Martin-Aigner/dp/364200855...

discusses the art gallery problem, among many interesting mathematical problems, and then exemplifies the playful spirit of mathematical proof by including in that discussion a photograph of what is quite possibly the ugliest art museum ever built--on the campus of my alma mater university.

http://www1.umn.edu/twincities/maps/WeismanArt/photo.jpg

(The photo shown in the book is different from this official photo, but you get the idea.)

For the rest of my life, I will always smile when I think of the art gallery problem, because it will remind me of what the authors of Proofs from THE BOOK asked their readers about the Weisman Art Museum (which I refer to as the "Ugly Art Museum"). Thanks for making me smile by submitting this link to the Wikipedia article.