The first environment I thought I would research into was Disney Pixar's Ratatouille as I really loved the French architecture and rustic style of drawing in the concept artwork.
I found it really interesting to watch this video and see how real life still holds such a strong influence when designing any environment.
These are concept drawings by Dominique Louis. I adore his use of colours and understanding of lighting, it makes these images so much more believable.
I also found these concept images for Ratatouille, taken from the 'making of' book.