You're taking a long road trip and you decide to stop for the night. While looking for a place to stop for the evening, you a historic looking building and decide to stay in it for a night or two. But it isn't until a few days later, when you look through photographs you took while at the hotel that you realize that they are missing. And it isn't until months later that you try to return to that same hotel that you can't find it anywhere at all.
Time slips are a phenomena where someone travels through times with unknown means. One of the more popular cases is in 1979, a couple traveling through France stumble upon a historic hotel during their travels. They ate food, took photographs, and paid an unreasonably low price for their stay. When they came home, they realized that their photographs were missing from their camera and when they tried to find the hotel again, it was nowhere to be found.
I love things like this and I'm fairly sure if I could "time slip" anywhere it would be time slip in Europe during the Medieval Times. To actually enjoy the real "medieval times" outside of the attraction.
And now that I brought up Midevial Times, I have to share this clip with you -