The City of Rosohna

{t}: Add {u}.

Channel — {3}{u}, Discard this card: Return target
artifact, creature, enchantment, or planeswalker to
its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Meaning "Rebirth" in the language of the drow, Rosohna is a vast metropolis in almost perpetual night, alight with thousands of small, sparkling arcane lanterns.