Many (Maybe 10) years ago I stumbled upon this website where:
People would post a picture. Sometimes this would be totally outside, sometimes out a window. Then people would try to figure out where (pretty much exactly) this place was on the earth. I remember this from time to time, and spend awhile googling and never come up with anything. Does this strike a bell for anyone?
It ran off a bbs, with lots of different things going at once, and it was photos not google maps, but that is an interesting site.
If it was a BBS, you are looking at 30 to 40 years ago.
There was an old door game called “Find Me” which meets your criteria except not being a website. Cannot find a link to it on Google but that is what you are describing.
The modern equivalent of this might be the r/whereisthis subreddit.