Detect Evil and Good

Casting Time: 1 action
Range: Self
Duration: Concentration, up to 10 minutes
For the duration, you know if there is an aberration, celestial, elemental, fey, fiend, or
undead within 30 feet of you, as well as where
the creature is located. Similarly, you know if
there is a place or object within 30 feet of you
that has been magically consecrated or
desecrated.
See PHB, pg. 231