An accidental natural space

At one time it was a test base for experimental military aircraft, but for the past 40 years it's hosted an antenna array.  The Air Force basically uses it to track anything that passes over the US in space.  It's part of a chain of similar stations across the country that act as part of a single antenna.

What it's done, as a side benefit, it to preserve a plot of land in one of the fastest developing areas in the country.  It's a common effect that military bases have.  In the process of guarding whatever they have there, they protect the natural resources of the site.  This has sometimes been a problem in the past - whatever the military has been doing there for the past 50 years suddenly comes under fire from environmental agencies because one of the last populations of some poor creature there, as a result of all of the surrounding private land being developed.   More recently, programs have been developed where agreements are signed where areas like this in Otay Mesa are preserved in exchange for continuing activities in similar habitat elsewhere.  Most military land isn't used directly anyway, the majority of a base is usually a buffer... they tend to need space between them and the public since they're usually either doing something dangerous, or in this case, just need to keep people away from something sensitive.

In any case, I get to travel down there, only about a 40 minute drive to just north of the Mexican border, to check up on the site, document that the things being protected are still actually being protected effectively.  It's a really cool spot, the canyons are untouched, still in their natural state while the surrounding lands are converted to endless housing tracts and industrial parks.