the angle honestly doesn’t work. at all. it’s clear that there’s nothing behind the large walls and the palace building (and everything in general) looks very very tiny, much smaller than it’s clearly supposed to be. this is not the city of a prosperous nation ruled by a firm and strong government, it’s a village with dreams of grandeour, ready to be smashed by raiders.
the rocky hill rising out of nowhere like that doesn’t really help. it just sticks out of the flat ground! that is not how natural ground formations work.
the icing on the cake is the lighting - you can NOT just light a huge scene with run-of-the-mill lamp setups and expect it to work. this is Source, an engine that by today’s standards is visually shit. the sun is very “uneven” in a way that can’t be just explained with clouds; i can rather easily tell where one lamp ends and another begins. that breaks whatever immersion one would desire to have in a shot. and then there’s the lack of any kind of atmospheric lighting, all shadows are pitch black. use this, always use this to get proper sunlight: http://forum.facepunch.com/showthread.php?t=1518642 . is this an SFM shot? many of the same principles apply anyway.
these elements come together to create something that looks like it isn’t natural, but rather thoroughly fake. no believability, no realism, no immersion.
you can fix the lighting and atmosphere issues by following the guide i linked. when in doubt, use very light fog (atmospheric haze) to create an illusion of distance, that always works.
for the scene setup, if you want something to look big and mighty, as the city of a powerful empire should be, make like the germans and shoot it from below, not above. shots from above are for belittling people, hunting prey and locating targets. things shot upwards are titanic, unbreakable and everlasting.
warmen, you should be amazed that Joazzz typed such a long text and trying to help you in the future and he said absolutely everything that is bad