What's that you say? You've never heard the harrowing history of the majestic sea lions of San Francisco's historic tourist attraction, Pier 39? After a brief hiatus in 2009 that had everyone freaking out, the sea lions are back at their posts, and this year they're "celebrating" their 24th Anniversary at the pier with brief, free tours that will tell the sea mammal's history as a part of the San Francisco Bay landscape. The estimated life span of a sea lion is 15-25 years, probably 30 at the most, so these may or may not be the OSLs (original sea lions). The special tours also offer free refreshments (probably cookies, probably at the end of the tour). And yes, if you're a local, it will require you mix and mingle and go elbow-to-elbow with outta-towners, but maybe try on Monday for smaller crowds and shorter lines at the Candy Baron.