In Genesis, Noah’s Ark had a door placed in its side.
Genesis 6:16 describes the ark as having a door in its side, along with lower, middle, and upper decks. The wording is part of the construction instructions given before the Flood. Genesis later says that Noah entered through this opening and that God shut him in.
The side door is a specific detail, not merely an artistic convention. Illustrators and filmmakers have depicted the ark in many forms, but the biblical description identifies the location of the entrance. It also presents the vessel as an enclosed, compartmentalized structure rather than an open raft.
The passage does not specify the door’s dimensions, hinges, or construction material. Nor does it call the opening a ramp. Those details belong to later interpretations and visual reconstructions. The canonical answer is simply “a door,” positioned in the side of the ark.