Down I-19 from Tucson you'll find the town of Green Valley, a peaceful and sprawling development area that seems to be a mecca for retirees. As peaceful as it is now, it was once the site of weapons of unimaginable destruction -- two Titan Missile silos buried in the hills.

These were two of 54 Titans deployed across the US. Holding 9-megaton warheads, always armed and ready to launch, they were the core of the United States' cold war-era strategic deterrent. With the proper authorization, they could be launched within 30 seconds of the turn of two keys. They were the tools of Mutually Assured Destruction.

Blast door #6

All the Titan silos are gone, stripped of their parts, de-commissioned, and blasted shut forever. Except this one. For $8.50 you can take a guided tour of this "dinosaur of the ICBM fleet", right down into the silo and into the control room, which is exactly as it was. The guide even demonstrates the procedure required to launch the missiles, which is really chilling when you think about it.

There is much more about the tour than I can tell here. The 8-foot thick walls, proof against blasts and electromagnetic pulses; the rooms suspended on giant springs; the incredibly finicky rocket fuels that required massive air conditioning in the Arizona desert; the strict rules against being alone anywhere near the command center. It's a fascinating place.

I've published about 11 photos on Flickr from the museum.

This evening yielded yet another spectacular desert sunset. I don't think I'll ever get tired of seeing them.