According to Genesis, what was Noah told to make around the Ark’s roof?

According to Genesis, Noah is told to make a cubit-high opening around the Ark’s roof.

Genesis 6:16 includes a difficult architectural instruction commonly translated as a roof, an opening, or a skylight extending to within a cubit of the top. English Bible versions differ because the underlying Hebrew wording is not entirely straightforward. Many translations describe a window or opening, while others describe a roof structure.

This detail is separate from the Ark’s side door, which the same verse mentions explicitly. It is also different from later artistic depictions that show a large hatch, a pitched roof, or many windows. Genesis does not supply a modern engineering diagram, so reconstructions depend on translation and interpretation.

A cubit was an ancient unit based roughly on the length of a forearm, but its exact historical value varied. The familiar biblical dimensions of 300 by 50 by 30 cubits are clearer than the precise design of this upper opening.