Hello Hiver,
Enjoying the moment of the sunset at the sea shore is a relief moment, the horizon line is look contrast, which is divided between the sky and the earth. Sky is the masterpiece of the almighty, that's why when look at the sky, we can have the relief feeling. The sun, which is slowly setting and hiding behind the cloud, resulting the gradation of brightness which is naturally seen the change of time. It is a natural sign that tells everyone that it's time for the moon to come up.
The horizon line is also the object that always interesting to look, its look like the borderline to another zone and the line point that meet among the sky and the earth.
Best Regard
@faizarfatria