A Night at the Forum has you exploring a piece of history in VR.
Mars Odyssey is a short, interesting VR experience geared toward people interested in the red planet.
Chernobyl VR Project brings a unique perspective to the abandoned city of Pripyat with some cool recreated areas to explore in VR. Unfortunately, there isn't a whole lot to do and the rest of the experience suffers from low res pics and vids.
Venture back to the first moon landing and you take part in this interactive experience that's pretty cool.