Among all the rabbit holes on the internet, there are a few I find especially deep.

If you are looking for ways to consume hours with no sense of time’s passage, I recommend that you:

1. subscribe to daily emails from Open Culture, which will notify you about a vast amount of tantalizing free content on the web: classes, books, movies, articles, art, science, politics – whatever your poison you can get it from here.
2. check out HistoryOrb, where you can see what happened on this day month year in history. Or many other days months years.
3. play the big (20×20 or 25×25) nonograms here. I find this numbers puzzle so addictive and a big one can take me 15-25 minutes to complete. It is hard to stop with just one and the next thing you know it’s Tuesday. (FYI, currently the game doesn’t work right with Chrome.)

Whatever you do, don’t share your own rabbit holes with me! (You can not share them in the comments below.)