really like how the bottom one overlooks the ruins :D
Pah-Pah! Now this is looking substancial! (:D I like the two lower ones , with the very last one being quite an exciting presentation of space.
try and watch out for repeating shapes and forms, especially in the natural elements. Three mountains in the background for example, it would really come to life by breaking up these bits.. Looking good thought.. Look forward to your colour explorations.