Dimension Gate - For a price in electrum you can pass to any other Dimension Gate.
Flight School - The only place to obtain the card Wings. Has extra quest givers.
Thieves' Guild - The only place to obtain the card Steal. Has extra quest givers.
Graveyard - Each turn spent in a graveyard allows you to add a Skeleton to your card pool.
Mine - Generates extra resources.
Casino - You can bet up to 50 electrum here per turn. You have a fifty percent chance to win double your bet.
Forge - You can buy rare weapons here; notably Farenheit, but very occasionally the other weapons.
Centrifuge - The only place to buy the card Momentum. Has extra quest givers.
Menagerie - You can buy random creatures, occasionally rare or otherwise unavailable, here.
Sanctuary - People within a Sanctuary cannot be attacked unless the Sanctuary is destroyed.
Pyramid - You can "save" your progress here, keeping a record of your electrum and cards. You may return to the Pyramid to go back in time to when you first arrived (and access your saved state).
The Lake Of The Gods - You can toss in an electrum here for luck. This may rarely give you some sort of blessing or boon.
Arena (only one) - Allows people to compete to become the Champion of their element - see other threads.
And another universal building:
The Alchemist's Workshop - Sells the appropriate elemental alchemy card (eg. Luciferin, Adrenaline), occasionally sells ones from other elements.
Additional rule: buildings can be
Sabotaged. Sabotaged buildings do not function until rebuilt by people from the team collectively spending a certain amount of electrum or resources. Sabotaging a building gives you a massive reputation drop with the relevant element.