"Welcome to our fine establishment. Now get the hell out!"
Take a close look at this door. Closer. Closer still. Even closer! Notice anything missing? How about the complete lack of a handle, knob or any other means of prying it open? There aren't even any visible hinges!
Maybe it's like one of those puzzle boxes. They want to keep the riffraff out and only those smart enough to figure out how to open the featureless door can get in?
Spotted at the riverboat casino here in town. No, I do not frequent the casino, as I don't have any money to spare to flush down the crapper while playing craps. It's next to the trail I walk every weekend that winds through town.