In preparations for the Apollo moon landings, NASA, in conjunction with the United States Geological Survey (USGS), created a simulated Lunar landscape in Arizona's Cinder Field. This basically involved making craters using high explosives. The details are more interesting than the basics. You can read all about it in io9's reposting of a the Discovery News article, "When NASA blew gigantic holes in Arizona for the Apollo Mission."
Here's one of several photos from the USGS:
UPDATE: With a hat tip to Sascha Grant, here's another great site. It has even more photos and provides a map of how to find the place if your are ever in N. AZ. I borrowed another cool photo from the USGS: