Civ 5 crashing, exact save point attatched

[zanakanishi]

Not too sure what or why this is happening, it's close to the start (well, a good 100 turns in, but hey, i'm on marathon) I have done nothing special, just building a lot and cutting down a lot of trees, I was hoping someone who knows what they are doing could figure out the cause of the crash, mainly so I can continue playing that save, but also because i'm curious in general... It's that exact point after I press end turn that I get the crash, tested it a few times, exact same thing.

Thanks in advance!

Zanak.Civ5Save