A quick (timelapse) look at player-made building in sandbox MMORPG Camelot Unchained; First, the foundation:
Couple hours later, look from below:
Builder is Necromaniak, one of the players alpha testing game's building tool, C.U.B.E. and these images are not representative at all of game's art direction - it's just a demonstration of the choices and style of one player.
Buildings are not static - they can be connected to physics, voxel destruction and territory control on insanely huge maps - game servers are planned to have ~5000 concurrent players. Couple more screenshots:
It is still early i.e. rough and Minecrafty - lots of features, such as round or cylindric shapes, wide choice of textures or heraldry, are yet to be implemented. Building is 100% free form, which can lead to all kinds of unexpected and creative results...thou enemies can attempt to siege and destroy your creations - unless built in safe areas or offline, on player's own servers.
In other words, besides aesthetics and prestige - buildings will be crucial for infrastructure, economy and especially for defending and controlling conquered territories. Below is the video I used to make those GIFs in the beginning: