While I was out wandering the mainland roads of Second Life I came across a place I'd visited once before during my early days in Second Life.
The Second Life Historical Museum in the Phobos Sim (click the link for the SLURL)
If you have any interest in the history of Second Life, this is a neat little place to visit, there are exhibits on 2 levels that offer information on the history of Second Life. Among other things you will find maps of Second Life over the years, the story behind the Hippos, the James Miller Taxi Co., and info cards on other significant objects, places and events.
It's definitely on my list of must see locations in Second Life.