I think this is the logical place to put this. Anyway, I know there are some Colorado bees on here, so I wanted to mention a fun place we went to last weekend. Turns out, there are sand dunes in the middle of the Rockies. It's almost surreal how out of place they look (and they genuinely looked like they were computer graphics, which was bizarre), but we went with a family that has an 18mo and a 5yo and they had an absolute blast. DH and I enjoyed it too, though it was a bit hot for me once it got close to noon. Definitely recommend getting out there early. There's a decent campsite really close by, and that's where we stayed. It makes for a very interesting mix up on the usual "camping in the mountains" idea.

http://www.nps.gov/grsa/index.htm