As a note, guilds building and designing guild halls should follow carlo's advice in the following thread:
http://www.darkgrimoire.com/bb/ftopic72 ... Halls.html
No, it is not against the rules to put giant mountains in your Dundee guild hall, or giant lakes in your desert guild hall, or pet trolls and demons in your Worldbuilder Lane guild hall... it is not against the rules, but it is dumb. It speaks to a lack of creativity and roleplaying ability. Were I an up-and-coming new player searching for a home, I would not join a guild that couldn't even manage to invent a hall that fits in with the environment where it exists, because clearly the leaders of that guild lack roleplaying skill, and this is a roleplaying game, where roleplaying skill is somewhat important.
Also, there have been a lot of posts by myself responding to people in new guilds wanting things the last few days, where I say, basically, "Yes, but what have you done for the world?" The gods do not give ANY favor to guilds that do not add to the world or work for the betterment of the society or atmosphere. Creating a guild hall that is out of place and out of character does not help your guild rise in stature in the eyes of the gods... in fact, it diminishes it. =)
So pick the location of your hall carefully, and then use your creative brainpower to make something artful that FITS within the greater context of where your hall is placed, and is IN-CHARACTER, given the universe of this game-world and the things that exist here. You will be on your way then to creating a good guild worthy of honors.