Guillermo del Toro's version of At the Mountains of Madness.
I am not a particularly big fan of Lovecraft and I like del Toro but am far from a superfan, but I think this would be incredible.
Basically, there is a Lovecraft novel about these explorers that find a completely alien, fantastical looking city that is in ruins in the Arctic. They find some animals there that are freaky and are basically prehistoric. As they explore the ruins, they find out that these evil beings are out there and they all start to go insane.
Tom Cruise was going to star and James Cameron was going to executive produce it. He lined up around $150 million to film it, but it was on the condition that it would be rated PG-13, which del Toro balked at. Now it's in like permanent limbo. I would love to see del Toro's design of that city though, I think it would be amazing. He's one of the few guys who could create some legit looking monsters / elder gods for the cameras. Prometheus basically sealed it's fate, unfortunately.
http://uproxx.com/movies/guillermo-del-toro-mountains-madness/2/