"Where once had risen walls of 300 cubits and towers yet higher, now stretched only the marshy shore, and where once had dwelt fifty millions of men now crawled only the detestable green water-lizard"
H.P. Lovecraft, "The
Doom That Came to Sarnath"
Unfortunately most Mythos pages have long since disappeared, but if you have an active page, please let me know and I'll add it to the list.
Official Mythos Homepage: Still has some excellent articles and card files dispite the absence of continued support.
House of Tindalos: By far the best Mythos page out there, Guy's House of Tindalos is a veritable mine of useful knowledge and information.