In the older parts of Montreal, Quebec, you'll find lots of apartments with private entrances to the upstairs units accessible by staircases from the street. They are an iconic image of Montreal, and no one thinks it odd, even in the winter when they have to shovel snow from the stairs, or even de-ice them. They've been that way for more than 100 years, and many are so historical that they cannot be altered. They come in all kinds of configurations, twisty and steep to save space.
The reason for the stairs was the city's explosive growth in the 19th century. Housing units were stacked one atop the other, and they were limited in size. But the city mandated a strip of "green space" in front of them. Builders and landlords immediately saw a workaround to devoting indoor space to stairs. Even the Catholic church had an interest in outdoor staircases. Now they have become a part of the city's trademark. Read the history and the reasoning behind Montreal's many outdoor staircases and see some lovely pictures at Atlas Obscura.
(Image credit: mksfca)