The site of the first atomic bomb explosion (Trinity) at the northern end of the White Sands Test Range is open to visitors each year the first weekend of April and the first weekend of October.
If you have any interest in military history, this is a must see.
http://en.wikipedia.org/wiki/Trinity_(nuclear_test)
How to get there: http://www.wsmr.army.mil/PAO/Trinity/Pa ... ouses.aspx