Must sees while traveling

When traveling, what lands on your must see list? How do you find out about it?

I have found that sometimes the most interesting experiences are the unexpected ones.
In Richmond, Virginia we ended up at a National Historic Site b/c it was one of the few places open on Memorial Day and on a Monday. What caught my eye in the AAA book was "well preserved home from the 1930's". That intrigued me b/c the 1930 seems like a time you rarely hear referenced in Architecture. As it turns out, the home was that of Maggie Lena Walker. The home was interesting but the most interesting part was learning about who she was and what an amazing impact she had for change in her community and listening to her quotes. If you have the chance take some time to learn about her. She was the first female bank president, a suffrageist and a Civil Rights Activist long before the nation would face the crisis.