The antonyms for "leave in ruins" can include a combination of words that denote rebuilding, restoring, preserving and improving. These words include 'revive', 'restore', 'recover', 'reconstruct', and 'rejuvenate'. These antonyms suggest a positive connotation of bringing back to life that which has been damaged or destroyed. A building, a community or an environment that has been left in ruins can be transformed into something beautiful, thriving and productive through intervention and care. Rather than leaving something in ruins, the antonyms suggest a pro-active approach to the challenges of the world, and a determination to make things better for future generations.