Inside the Noah's Ark

ark (n.)
Middle English arke, from Old English earc, Old Northumbrian arc, mainly meaning Noah's, but also the Ark of the Covenant (the coffer holding the tables of the law in the sanctum sanctorum), from Latin arca "large box, chest" (see arcane), the word used in the Vulgate.
arcane (adj.)
"hidden, secret," 1540s, from Latin arcanus "secret, hidden, private, concealed," from arcere "to close up, enclose, contain," from arca "chest, box, place for safe-keeping," from PIE root *ark- "to hold, contain, guard" (source also of Greek arkos "defense," arkein "to ward off;" Armenian argel "obstacle;" Lithuanian raktas "key," rakinti "to shut, lock").