Repost from a comment I made in a thread in the general forum.
An entire area that was all canals instead of streets - the Venice of Ur - would be fantastic (in all senses of the word). You'd need to work your way up the boating (from row boats to punts to gondolas) skill tree to get around efficiently. The palazzi would be quite pricey, and you'd need to own your own boat to get in and out quickly, but the views down the canals would be exquisite!