The gardens of Vaux-le-Vicomte are terraced and end at a hill overlooking canals and grottos. In the center of this beautiful hill is a statue of mythological significance. Who is the subject of the statue, and what event (or feat, shall we say), does the statue "commemorate."

On the hill at the end of the gardens is a statue of Hercules. He is depicted standing and resting, leaning on something, after performing the last of his "labors" or feats. As far as I can tell, it does not show him performing any particular feat.

http://en.wikipedia.org/wiki/Farnese_Hercules

The statue on the hill at the end of the gardens of Vaux-le-Vicomte is a depiction of Hercules. The statue does not specifically commemorate any particular event or feat, but rather represents Hercules in a moment of rest after completing his famous Twelve Labors.

To find the answer, I conducted a quick search on the internet using the provided information. The link you shared leads to the Wikipedia page about the Farnese Hercules, which is a famous sculpture depicting Hercules. The description of the statue on that page confirms that it represents Hercules in a resting pose, leaning on something, and it does not illustrate any specific feat.

By referring to reliable sources like books, scholarly articles, or trusted websites, you can gather information regarding historical and mythological subjects such as statues, artworks, or events. Remember to critically evaluate the sources and cross-reference information to ensure accuracy and reliability.