Please Use Revolving Doors
This sign is at the Royal York Hotel, Toronto. It’s a pretty common sign, often found on the complex doorways of hotels, universities, office buildings, etc. For climate control reasons (as some signs like this make clear) they want you to use the revolving door, rather than the swinging door that is much more likely to allow in a gust of cold / hot / etc wind.
Such signs can be mildy irritating, especially since you generally end up reading them as you’re just about to do something other than what they’re asking you to do.
Also worth noting: if you look below, you see the sign actually appears twice, which gives the whole thing a lovely air of onomatopoeia. Say it out loud: “please use revolving doors, please use revolving doors, please use revolving doors….”
Thanks to Yoni Freedhoff for sending the pic!