They found a big hole on the moon...almost 200 feet accross and about 250 feet deep that they think it might connect to a lava tube tunnel which could be about 1200 feet wide. If so, I think we have a great location for our moon base.
http://www.newscientist.com/article/dn18030-found-first-skylight-on-the-moon.html
http://www.newscientist.com/article/dn18030-found-first-skylight-on-the-moon.html