This isn't just about crimes like the identity of Jack the Ripper, DB Cooper, the fate of the two English princes locked in the Tower of London, or what happened to Jimmy Hoffa. There are so many mysteries throughout history that are unlikely to ever be fully solved or explained, that we can only theorize about.

What is the Voynich Manuscript? Who was the Man in the Iron Mask? Why was the Mary Celeste abandoned? What's up with the Dyatlov Pass Incident? What's the real story behind the Pied Piper of Hamelin? What did Anne Boelyn really look like?

There's an infinite wealth of mysteries throughout history, so which ones do you find the most intriguing? Bonus points if they're more obscure, or a smaller local one!

This is one of those mysteries that I haven't been able to solve. For context, I was hiking Pima Canyon back in 2017 or 2018. I was with another hiker. After about a mile or so, the other person said they needed to take a break, so I decided I would get a quick trail run in. I started jogging further along the path, dodging boulders and cacti.

After about another mile (so I'd guess two miles into the hike from the trailhead), I heard a sound. It was one of those situations where your brain doesn't know how to interpret what it is sensing, so it fills something in as a placeholder. In this instant, I thought it was the sound of someone starting a lawnmower. It was a brief sound -- maybe 1 second in duration. It also sounded close to me.

As soon as I came to the realization that nobody was mowing their lawn out here, I felt very threatened. I bent down and grabbed the largest rock I could find, and turned around and started walking back down the trail. After a few minutes, I picked up the pace and sped back to the other hiker.

To this day, I have no idea what that sound was.