What are the best exploration based games on PS4?

NieR: Automata is set in an apocalyptic time where Earth has been overrun by robots, and the artists really nailed what that would feel like. Abandoned and overgrown cities litter the landscape along with old refineries, graveyards, and eerie forests. When you add the beautiful soundtrack to the experience, it fills you with a bittersweet mix of loneliness and hope.