I've learned a great amount from Piero Scaruffi's encyclopedic music history website: https://www.scaruffi.com/<p>Robert Braeunig runs an orbital mechanics site: http://www.braeunig.us/space/orbmech.htm
This might not be what you're looking for, but this is a very old site that has never changed. It's a french language page call "perdu.com" which simply means "lost". The content simply translates to "You are here" with an arrow and an "X" to mark the spot. It's not usefull in any way, but it always makes smile.