In the Genesis Noah's Ark account, the building instructions specify a single door for the ark.
Genesis 6:16 tells Noah to put a door in the side of the ark. The same verse describes a window and three levels, creating a short but distinctive architectural description. The door is not presented as one of several entrances or as a named gate.
Later in the story, after Noah and the animals enter, Genesis says that the Lord shut him in. This detail gives the door a narrative role as well as a structural one: it marks the transition between the safe interior and the world outside during the Flood.
Translations may vary slightly in wording, sometimes using “door” or “entrance,” but the standard answer to the architectural question is door. The text does not call it a hatch, port, or gate and does not describe its dimensions.