Oakland 16th Street Station
A group called Urban Living Tour is offering a tour of the station, along with other hidden gems of Oakland. The tours run from 11am-5pm today (Sunday, September 16th). The cost is $20 for the entire tour (if purchased in advance), and the proceeds from the tickets benefit Rebuilding Together Oakland.
Note: After digging through their website a bit more, I realize that tickets are $20 in advance, and $30 at the door...And you can't buy them at the train station. You have to buy and pick up tickets at the registration office....Please check the website for more information because I feel like I'm at the point of getting myself confused and giving out wrong information).
More information about the tour is available at the Urban Living Tour link above. There's also a nice history of the station available at the San Jose Mercury News.