indistinguishable

Not distinguishable; not capable of being perceived, known, or discriminated as separate and distinct

The banks of the old railway are now so thickly overgrown with trees as to be almost indistinguishable from the surrounding countryside, and the most obvious landmarks are the walls of a bridge over a lane, and stone bridge, still intact, where a cart road crosses the cutting, close to the site of the former Clifton South Junction.

Any sufficiently advanced technology is indistinguishable from magic

Not capable of being perceived or known.

Any of a set of things that cannot be distinguished.