What does the ancient poem "Climbing the Stork Tower" and the last two sentences mean?

Climbing the Stork Tower

A regular script carved stone rubbing by Academician Zhao (Xuanhuang) "Climbing the Stork Tower"

Tang Wang Zhihuan

The day is over the mountains, and the Yellow River flows into the sea.

If you want to see a thousand miles away, take it to the next level.

Translation:

The setting sun slowly sinks against the Western Mountains, and the mighty Yellow River rushes towards the East China Sea.

If you want to see enough of the thousands of miles of scenery, you have to climb to a higher tower.