My fiance and I are moving from Philadelphia to San Diego at the end of July/beginning of August and we'll be doing the cross country drive so we can see some of the beautiful scenery in between! We're planning to take at least one and maybe two weeks for the trek. I'd love some advice on what route to take and what to see along the way. Most of the things I have on my visit wish list so far are in NM, AZ, UT, and NV: Grand Canyon (of course), Las Vegas, Carlsbad Caverns, and Zion National Park to name a couple. So, suggestions on where to go/what to see in the middle of the country would be great! Especially anything to do with national parks or good museums.