Understanding 'Serene' in Context

In the midst of the bustling city, the small park was a sanctuary for all who sought a moment of peace amidst the chaos. Nature flourished there, with vibrant flowers blooming boldly and trees standing tall, offering a refuge from the concrete jungle surrounding it. Lately, however, the serene ambiance had been disrupted by a persistent group of noisy children, whose raucous laughter echoed off the buildings nearby. Some visitors, frustrated by the uproar, began to whisper about a potential solution to restore the park's tranquility.

In this context, the word 'serene' most nearly means: