Cool niche websites

Just wanted to share some cool niche, maybe "obscure" websites on this list. I encourage others to share, but of course make sure the content is age/list/group appropriate (generally I would suggest the content be all-ages appropriate)

https://hmpg.net/ - the end of the internet!

https://tropical.theferns.info/ - Useful Tropical Plants Database

https://wiby.me/ - Old(web) and simple website search engine

https://www.naturalarches.org/ - The Natural Arch and Bridge Society

http://ibm-1401.info/ - IBM 1401 Demo Lab Museum and information Webpage