In the Genesis flood account, the ark’s main entrance was made into its side.
Genesis 6:16 gives construction instructions that include a door placed in the side of the ark. The verse also mentions a window and three decks, creating one of the few compact descriptions of the vessel’s physical arrangement in the biblical text.
The wording is specific but limited. Genesis does not describe the door’s exact dimensions, hinges, materials, or opening mechanism, and later paintings and models supply details that are not stated in the text. The side entrance is also separate from the window mentioned in the same verse. That distinction makes “its side” the precise answer rather than a general response such as “the front.”