I’m rushing to post this, or I’ll spend all clicking around at https://www.populationspast.org/.
The website lets you make and see maps that show how people lived in different places and times from 1851 to 1911. Curious about an area in your family history; how many babies were born and died, who got married, where people came from, who they lived with, how old they were, what jobs they had and how crowded their areas were? Zoom in on a map to see a smaller area, and compare two maps of different times or things. The maps show Registration Districts for England and Wales — zoom in to see Registration Sub-Districts except for Scotland where only RDs show.