While researching for an article, I came across an interesting post forum post which I wanted to use as a reference.

Before I could finish my article, the forum site I wanted to reference was officially shut down, making the aforementioned forum post inaccessible.

Thankfully I was able to find an archived version of the post on The Wayback Machine, but I'm not exactly sure how to reference it.

How should I cite an archived version of a webpage if the original webpage is no longer available? Should I add a "Date Accessed" note to my original citation, or should I cite the archived version instead?