For the duration, you sense the presence of secret doors, concealed traps, and areas hidden by magical or mundane covers within 30 feet of you. If you sense a secret in this way, you see a faint aura around the secret, such as an aura outlining a secret door, a glow highlighting a trapped flagstone, or a shimmering across the illusory wall that hides a passage beyond it.    A secret door or hidden area, for the purpose of this spell, includes anything purposefully hidden or concealed in some way by its creator. A trap, for the purpose of this spell, includes anything that would inflict a sudden or unexpected effect you consider harmful or undesirable, which was specifically intended as such by its creator. Thus, the spell would sense an area affected by the alarm spell, a glyph of warding, a mechanical pit trap, a leaf-covered pit, a door behind a hanging tapestry, or a door flush with a stone wall that is opened by a pressing a specific stone. The spell would not reveal a natural weakness in the floor, an unstable ceiling, an evil tome “hidden” in plain sight alongside other books, or a crystalline phylactery “hidden” in a display case with other crystals.    This spell merely reveals a secret’s presence and its location. You don’t learn the methods of opening, disarming, or otherwise bypassing or revealing the secret, but you do learn the general nature of the secret and, if it is a trap, the danger it poses.    The spell can penetrate most barriers, but it is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt.