That tiny door built into the side of an older house may look mysterious, but it was often a milk door, designed specifically for early-morning milk deliveries.
Milkmen could place glass bottles through the small opening, which often led directly into the kitchen, allowing families to collect fresh milk without opening the main door.
These convenient little doors were especially common in the early to mid-20th century, before modern refrigeration and changing shopping habits made daily milk delivery less common..READ MORE BELOW