Grandes Edificios

Construction
To place a great building, you need the following: The nine different blueprints of that building An amount of goods from that building's age Once you comply with the requirements, you can place the construction site. But that doesn't give you the building yet – see section Levels.
Blueprints
Every great building is a puzzle of nine pieces, which you have to collect in order to construct the building. That can be achieved in the following ways: Polish or Motivate your neighbours/guildmates, Plunder your neighbours, though chances to find something are a little lower than with polishing/motivating, Help other players construct their great buildings (see section "Donation Rewards"), Diamonds, once you found at least one blueprint of that building one of the other ways. Quests and the Treasure Hunt can also give you random blueprints Special events may feature blueprints as prizes When Polishing/Motivating/Plundering, the affected building's age defines what blueprint you might find. Example: If you motivate a pottery, a Bronze Age building, you can only find blueprints for the Statue of Zeus or the Tower of Babel – Great buildings of Bronze Age. You can also trade two duplicates in a specific Great building for one blueprint in that same Great Building (but still in a random spot) if you are still looking to get a specific spot.
Levels
Once you placed a great building, it's on level 0, like a construction site. Unlike other buildings, these don't build up themselves, but have to be constructed with the use of forge points. When the building reaches level 1, it is finally built, but can be upgraded to level 10 with forge points alone. You will then need set of blueprints to unlock levels past 10 (one set = one more level available). The higher the building's level, the more powerful the bonus becomes and the greater the amount of forge points are needed to reach the next level. Details on the forge-point costs and bonuses can be found in the respective posts of each building.
Bonuses
Of course the great buildings aren't just a waste of space, but grant powerful bonuses that grow with the building's level. Depending on the building, you might get the following: Military boost: Raises the attack and defense bonus for units in attacking army, adds up with every building Fierce resistance: Raises the attack and defense bonus for units in defending army and increases support pool bonus, adds up with every building Coin boost: Raises the outcome of your houses up to 90 times with each collect, adds up with productivity and motivation Supply boost: Raises the outcome of your production buildings, adds up with productivity, motivation, and other supply boosts. Good Production: Produces a certain amount of goods from your current age every 24 hours. From Modern Era on, produces double the amount in unrefined goods. Medal production: Produces a certain amount of medals every 24 hours Research: Produces a small amount of forge points every 24 hours Coin production: Produces a certain amount of coins every 24 hours Supply production: Produces a certain amount of supplies every 24 hours Population: Permanent population bonus Happiness: Permanent happiness bonus Quest reward boost: Raises only your coins, supplies, goods, medals, or diamonds from quest rewards. Penal Unit: Recruits unattached units every 24 hours, randomly chosen from any military building in your city. Guild Goods: Produces current era goods which go straight to the Guild Treasury. Support Pool Bonus: Raises your guild's support pool bonus, adds up with every building Aid Goods: Produces 1 random good when aiding another player's city (manually motivating/polishing them also counts as aiding). The age of the random good corresponds to the age of the building you are aiding. Plunder Goods: Produces random goods for up to 3 neighbors with each collect when plundering another player's city. The age of the random goods corresponds to the age of the building you are plundering. Contribution Boost: Raises the Forge Points, Medals, and Blueprints you receive from donation rewards. Aid Blueprints: Raises the chance of obtaining a blueprint when aiding another player's city (manually motivating/polishing them also counts as aiding). I.E. Having a 100% bonus will double your chance of finding a blueprint