Probably the most common among Brookfield kids, this site is better for more than impressing your girlfriend by making out with her underneath the tower. Climb the inner metal structure of the radar launch to reach the top, where you can see out over a hill toward the lights of Capitol (romantic, I know). Then, climb on down and break into the old storage building to find what is referred to as "the Dungeon," a spooky and mostly-unexplored warehouse of Cold War remnants.
Search "Hillcrest Park" in your map app. Park wherever you want in Hillcrest. The tower that you can climb should be obvious as soon as you arrive, but the building is harder to find. It's not the one you see when you drive in - it's the one by the giant fenced-in area to the right of the Missile Launch radar tower. The door to the leftmost side (closest to the tower) is the one easiest to open. Good luck!
During the Cold War, the United States was peppered with Missile Launch sites, like this one owned by Nike. The tower that everyone climbed never contained a missile, but was instead a radar tower for monitoring the area. There was originally a ladder that would take workers to the top, but it was stripped when the site closed down. You can still see the metal sides of where the ladder used to be. The only remaining way to climb the tower is to go up the metal structure inside and through a hole.
The actual missile was kept in the large concrete area that is still fenced off. Any extra equipment belonged in the building below this, now known as "The Dungeon." Workers at the site have told me that they aim to convert this building into a small Cold War museum in the next few years since they're sick of "intruders" like myself.
Have you been to these tunnels? What did you think? Leave any tips of your own or observations in the comments to help other explorers!