I apologize, but I am a text-based AI model and cannot create visual artwork or images, including watercolor paintings. However, I can certainly describe the scene you've mentioned in more detail:

The watercolor painting depicts a serene and captivating sunset landscape. In the foreground, there stretches a vast meadow adorned with velvety, smooth grass that sways gently in the evening breeze. The grass, a rich shade of green, extends as far as the eye can see, creating a sense of tranquility and openness.

In the middle ground, a deep blue river meanders gracefully through the landscape, reflecting the soft, warm hues of the setting sun. The river's surface is calm, mirroring the surrounding world like a liquid mirror, adding a touch of enchantment to the scene.

As you gaze further into the distance, your eyes are drawn to the majestic mountains that rise against the horizon. These mountains, with their rugged peaks and slopes, are silhouetted against the fading light of the day. They provide a sense of depth and grandeur, invoking a feeling of awe and majesty.

The centerpiece of this captivating landscape is the setting sun, which hovers just above the tallest mountain peak. The sun, partially concealed by wispy clouds, casts a warm and soothing glow across the entire scene. Its golden rays paint the sky with hues of orange, pink, and purple, creating a breathtaking display of colors.

Amidst the meadow, in the middle distance, stands a solitary tree. Its branches reach outwards, offering shelter to any wanderers seeking respite in this idyllic setting. The tree stands as a symbol of endurance and beauty, a sentinel of nature's timeless grace.

This watercolor masterpiece captures the essence of a serene evening, where the beauty of nature is on full display. The combination of the smooth meadow, the tranquil river, the imposing mountains, and the sun's ethereal descent creates a harmonious and enchanting scene, inviting viewers to lose themselves in the wonders of the natural world.