The Trinity Site is the location of the first atomic bomb explosion, and as it is on an active military facility (White Sands Missile Range), is only open one day each year on the first Saturday in April.
http://www.wsmr.army.mil/PAO/Trinity/Pages/default.aspx
Visitors turn off Hwy. 380 and drive 5 miles south to the Stallion gate (12 miles east of I-25 or 54 miles west of Carrizozo, NM). Alternatively, visitors can meet up with a caravan in Alamogordo, NM.
We spent Friday night in Carrizozo at the Four Winds Motel, a traditional motor inn with very clean and recently renovated rooms, then made the drive Saturday morning.
The line of vehicles to enter was appx. 1 mile long when we arrived, around 9 AM. All visitors must stop at the gate and show identification. It is an additional 17 miles from the gate to the Trinity Site parking lot.
Jumbo
Outside the outer gate is the remnant of the Jumbo casing – originally designed to prevent plutonium from being lost if the chain reaction failed to occur. However as the scientists gained confidence in the bomb design, plan to use Jumbo were suspended. (The ends are missing as the Army detonated eight 500-pound bombs inside it in 1946.)
From the outer gate, it is a 1/4 mile walk to ground zero.
Inner Gate
Lava Rock Monument – Ground Zero
Radiation at the site is low, just 10 times greater than the area’s natural background radiation. A one hour visit to the Trinity Site is equivalent to 1/2 of one millirem. By comparison, a coast-to-coast flight has an exposure of two millirems.
Fat Man Bomb Casing
Panorama View
In all, we spent around an hour at the site. Unfortunately, the military was not running the optional bus tour to the McDonald House, where the bomb was assembled.
Honestly, there isn’t a lot to see: Ground Zero monument, a metal footing from the tower, Fatman bomb casing, and a metal shelter protecting part of the original crater. There are also historical photos etched in metal around a portion of the fence. But this is more about the historical significance of the site than the actual things to see. There were people present from all over the world, as I heard German, Japanese, French and a Scandinavian language,
Am I glad we went? Yes. Will we go back? No.