What is the couplet of Water Curtain Cave in "Journey to the West"?

The couplets of Shuiliandong in "Journey to the West" are as follows:

The couplet is: The blessed land of Huaguo Mountain, the cave sky of Shuiliandong. This couplet means that the Water Curtain Cave in Huaguoshan is a geomantic treasure. Water Curtain Cave is a famous scene in the Huaguo Mountain Scenic Garden. It is located on the top of the mountain, on the east side of the Reunion Palace of the Sanyuan Family Temple. The author uses romantic techniques to depict a wonderful mythical world. The couplet at the entrance of the Water Curtain Cave in Huaguo Mountain is one of the outstanding expressions.

Characteristics of Shuiliandong:

Going eastward from the Tuanyuan Palace, you can see the "blessed land of Huashen Mountain and the cave sky of Shuiliandong" deliberately described in "Journey to the West". According to legend, it is the place where three elements are cultivated.

Shuilian Cave is a natural cave with a "human" shape entrance facing south. The cave is like a hall, and there is Mengquan inside. "The winter is endless and the water is very sweet." Therefore, it is said by the saints that this spring is The mouth of the sea is called "Sea Eye". It is said that Sun Dasheng Dragon Palace borrowed treasures from here from here.

There is a trickle of water on the cliff outside the cave. "If you look carefully at the drops of water on the cliff, you may think they are pearls rolling down the curtain." On the cliff, there are eight characters inscribed by the prefect Wang Tong in the 23rd year of Jiajing in the Ming Dynasty (1544): "High Mountains and Flowing Waters" and "Shenquan Purun". The text clearly metaphors the word "water curtain".