If you're a lucky person, you have made it to Culver City, California and raked up the courage to walk to a locked door on a busy city street, and ring the buzzer once, only to hear it swing open, and be ushered inside a blindingly dark and deafeningly quiet room.
The entrance to The Museum of Jurassic Technology.
When I tell people about this place, I always struggle for just the right descriptors - I'm sure people call it "weird" or "creepy", but it's not really those things, and every bit those things at the same time. Very few places strike me as "forbidden", and as I wandered around the windowless, curtained rooms of this modern museum, I couldn't help but feel like I was somehow given permission to see this place, it is so occult, so secretive.
Realistically, it is open to the public nearly every day, and for a modest admission fee you are free to roam the rooms and even have some Russian tea and cookies in an upstairs tearoom.
But if the daunting, quiet, dark atmosphere isn't enough to throw you, the exhibits probably will. It's a self-titled "educational institution dedicated to the advancement of knowledge", but what that knowledge is, and the degree of its provability or scientific integrity is often debatable.
Topics from old folk remedies to humans growing horns, to tiny sculptures within the eyes of needles, to a very large and involved display about the (alleged) capture of the (alleged) Deprong Mori, a bat-like creature who can use its sonar to move through solid objects.
I can't say enough good, strange, or fanatical things about this place. If I lived in Southern California I would definitely be a regular patron, and go a few times a year.
There is a great book written about the museum, which I read a couple of years ago, and wrote a fairly lengthy journal entry about. If you've been to the museum, I highly recommend the book, and if you haven't been there, book a flight now.
Edited to add: here is a Wikipedia article on the MJT.