When searching for antonyms of "most unspoilt," we can consider words like tainted, spoiled, polluted, corrupted, or spoiled. The opposite of "most unspoilt" is something that has been negatively impacted, affected by the human activities, or deprived of its natural beauty. This can apply to a city, a landscape, a forest, or a beach. For instance, we might say that a city that has been destroyed by pollution and overcrowding is the opposite of "most unspoilt." A landscape that has been marred by industrialization or erosion can also be antonymous to the phrase "most unspoilt." Ultimately, antonyms for "most unspoilt" refer to the damage done to something pristine, natural, or untouched by human hands.