One thing that bothers me is that the "bridges", at least the two lower ones, look so round while the platform has some sharp edges. I guess this kind of landscape would appear when the ground erodes around it. This would probably leave those small passages with clean edges as well. However, this isn't really taking much away from the piece since it's already fantasy and pretty unnatural.
Other than that, IT'S AWEESSOOOMEE. YEAAAH! Especially love the moody haze, those epic pillars and that small road crossing the mountain wall.