The Cool Riddles Project
e-riddles.blogspot.com
e-riddles.blogspot.com
Having said that - good luck. I literally know hundreds of these, and a raw collection is pretty pointless - I'd love to see how you intend to organise these.
Consider also the paradox of choice. I would expect that most visitors will be overwhelmed and bounce.
The design is not to my personal taste, and nearly unusable on my mobile. I have no idea how big the site is so far, because it's impossible to navigate on this device.
So there's some quick feedback. It's an interesting challenge, and I wish you luck!