The Rabbithole can be found on the sidebar of the LEVELS site.
Clicking the Rabbithole causes the user to move to the /rabbithole/tunnel.html page, containing a quote from the book Alice in Wonderland. From the tunnel page, users can get to the /rabbithole/falling.html page, which is appropriately trippy.
After falling down the rabbithole, the user is redirected to the Hallway.
The Rabbithole was originally found through an audio clip accessible by calling the number listed on the sidebar. When called, the recorded message would play:
“In another moment down went Alice after it, never once considering how in the world she was to get out again.”
Going to the page /rabbithole/ redirected to the tunnel page, which originally contained a standby message.
After the original Rabbithole was found, LEVELS posted twice on their twitter account:
These tweets, the first referencing the name of the Doormouse in the Alice in Wonderland movie, and the second more directly referencing the Jefferson Airplane song, lead to the page /rabbithole/feedyourhead.html
At night on 3/19/17, the LEVELS home page started displaying text which would fade in and out over the main page. This was removed after ~1 week.
The text translated to
"But I don't want to go among mad people," Alice remarked.
"Oh, you can't help that," said the Cat: "we're all mad here. I'm mad. You're mad."
"How do you know I'm mad?" said Alice.
"You must be," said the Cat, "or you wouldn't have come here."
Which lead to the /rabbithole/hatter.html page.