My purpose here is to list they types of GP farms one can build by combining different national wonders with National Epic. I list what I believe to the five most likely candidates, in the order that I like them, from worst to first.
1. The Military Production GP Farm
Second National Wonder: Heroic Epic
Advantages:
Allows you to concentrate your most powerful city on building military units and GPs at the same time.
Heroic Epic comes early, allowing you to bring your best city completely up to speed quickly.
Good for early conquest and domination efforts.
Allows you to put West Point together with Iron Works for a separate military city, or to put one of them together with Globe Theater for a happiness-penalty-free whipping/drafting city.
Disadvantages:
Requires you to spend hammers on military units, rather than concentrating on things to help your GP farming (such has happiness or health improvements, or other wonders).
Prevents you from putting Heroic Epic together with West Point (or Ironworks) in a separate super-military city.
Terrain desirable for military production may produce little food, and thus not be conducive to GP farming.
2. The Science GP Farm
Second National Wonder: Oxford University
Advantages:
Often a good choice for a capital, with terrain conducive to commerce improvements, where early wonders have been built.
Bureaucracy civic adds both commerce and hammers to your capital, increasing science as well as building potential for other wonders and health and happiness improvements.
May allow you to combine Oxford University with Great Library, though possibly only for a short period of time before Scientific Method kills the Great Library.
Disadvantages:
Working commerce improvements will limit food production and population, decreasing the availability of specialists, thus decreasing GP production.
Cities suitable for cottages may have low hammer potential, interfering with the building of wonders or health and happiness improvements.
Building science improvements may interfere with building of wonders and health and happiness improvements.
3. The Pure GP Farm
Second National Wonder: Globe Theater
Advantages:
Allows you to increase population without limit, and without having to spend hammers building happiness improvements.
Hammers saved not having to build happiness improvements can be used to build other wonders, adding GP points.
Disadvantages:
Unlike the others listed here, does not provide a significant side-benefit to the GP farming.
Population growth may still be limited by health issues.
4. The Money/Religion GP Farm
Second National Wonder: Wall Street
Advantages:
Combine merchant and priest specialists with shrines and other wonders for huge money and huge GP points.
Good choice for spiritual civs with religions founded in their capital, where other wonders might already exist.
Shrines do not require hammers to build, but contribute to GP points, allowing the city to focus on other wonders and improvements.
Great Merchants built here can settle in the same city, further increasing money and adding free food.
Disadvantages:
Not as advantageous for non-spiritual civs with religions founded in cities other than the capital, as it deprives the GP farm of wonders probably built in other cities.
Dealing with unhappiness from expanding population will be a near constant problem.
Prevents you from being able to combine Wall Street with Globe Theater for an unlimited-population religion/money city.
5. The Engineer GP Farm
Second National Wonder: Iron Works
Advantages:
When brought up to speed, allows employment of up to six engineer specialists (which cannot otherwise be obtained, such as through caste system).
Farms Great Engineers, which are the most useful GPs, particularly in the late game.
Hammer bonuses from the Iron Works and engineer specialists will assist in building health and happiness improvements, as well as other wonders.
Great Engineers born here can be used in the same city to build other wonders, or in low-hammer cities to produce needed improvements (such as Oxford in a separate science city).
Disadvantages:
Placing Iron Works in a city set up for GP farming prevents you from putting Iron Works in city with a lot of terrain-based hammers, thus losing production which could be used for military units, etc.
Engineer-producing wonders and ability to employ engineer specialists are limited, so you will either be limiting your GP production, or “polluting” your GP production with a lot of non-engineer points.
Iron Works comes late in the game and is difficult to build (although a Great Engineer helps a lot).
Iron Works and Factory cause extra unhealthiness, thus limiting growth and/or requiring building of health-improving structures.
A couple of closing notes: Of course, you can have other GP farms that don’t involve National Epic. I’ll usually have 2 or 3 cities dominated by farms and specialists, such as a religion/money city (with Wall Street and Globe Theater, when I don’t combine one of those with National Epic in the main GP farm).
Also, these are not the only possible combinations with the National Epic. You could have the Culture GP farm (Hermitage), the Spy GP farm (Scotland Yard) or the Medic GP farm (Red Cross). Those others just didn’t make much sense to me.
1. The Military Production GP Farm
Second National Wonder: Heroic Epic
Advantages:
Allows you to concentrate your most powerful city on building military units and GPs at the same time.
Heroic Epic comes early, allowing you to bring your best city completely up to speed quickly.
Good for early conquest and domination efforts.
Allows you to put West Point together with Iron Works for a separate military city, or to put one of them together with Globe Theater for a happiness-penalty-free whipping/drafting city.
Disadvantages:
Requires you to spend hammers on military units, rather than concentrating on things to help your GP farming (such has happiness or health improvements, or other wonders).
Prevents you from putting Heroic Epic together with West Point (or Ironworks) in a separate super-military city.
Terrain desirable for military production may produce little food, and thus not be conducive to GP farming.
2. The Science GP Farm
Second National Wonder: Oxford University
Advantages:
Often a good choice for a capital, with terrain conducive to commerce improvements, where early wonders have been built.
Bureaucracy civic adds both commerce and hammers to your capital, increasing science as well as building potential for other wonders and health and happiness improvements.
May allow you to combine Oxford University with Great Library, though possibly only for a short period of time before Scientific Method kills the Great Library.
Disadvantages:
Working commerce improvements will limit food production and population, decreasing the availability of specialists, thus decreasing GP production.
Cities suitable for cottages may have low hammer potential, interfering with the building of wonders or health and happiness improvements.
Building science improvements may interfere with building of wonders and health and happiness improvements.
3. The Pure GP Farm
Second National Wonder: Globe Theater
Advantages:
Allows you to increase population without limit, and without having to spend hammers building happiness improvements.
Hammers saved not having to build happiness improvements can be used to build other wonders, adding GP points.
Disadvantages:
Unlike the others listed here, does not provide a significant side-benefit to the GP farming.
Population growth may still be limited by health issues.
4. The Money/Religion GP Farm
Second National Wonder: Wall Street
Advantages:
Combine merchant and priest specialists with shrines and other wonders for huge money and huge GP points.
Good choice for spiritual civs with religions founded in their capital, where other wonders might already exist.
Shrines do not require hammers to build, but contribute to GP points, allowing the city to focus on other wonders and improvements.
Great Merchants built here can settle in the same city, further increasing money and adding free food.
Disadvantages:
Not as advantageous for non-spiritual civs with religions founded in cities other than the capital, as it deprives the GP farm of wonders probably built in other cities.
Dealing with unhappiness from expanding population will be a near constant problem.
Prevents you from being able to combine Wall Street with Globe Theater for an unlimited-population religion/money city.
5. The Engineer GP Farm
Second National Wonder: Iron Works
Advantages:
When brought up to speed, allows employment of up to six engineer specialists (which cannot otherwise be obtained, such as through caste system).
Farms Great Engineers, which are the most useful GPs, particularly in the late game.
Hammer bonuses from the Iron Works and engineer specialists will assist in building health and happiness improvements, as well as other wonders.
Great Engineers born here can be used in the same city to build other wonders, or in low-hammer cities to produce needed improvements (such as Oxford in a separate science city).
Disadvantages:
Placing Iron Works in a city set up for GP farming prevents you from putting Iron Works in city with a lot of terrain-based hammers, thus losing production which could be used for military units, etc.
Engineer-producing wonders and ability to employ engineer specialists are limited, so you will either be limiting your GP production, or “polluting” your GP production with a lot of non-engineer points.
Iron Works comes late in the game and is difficult to build (although a Great Engineer helps a lot).
Iron Works and Factory cause extra unhealthiness, thus limiting growth and/or requiring building of health-improving structures.
A couple of closing notes: Of course, you can have other GP farms that don’t involve National Epic. I’ll usually have 2 or 3 cities dominated by farms and specialists, such as a religion/money city (with Wall Street and Globe Theater, when I don’t combine one of those with National Epic in the main GP farm).
Also, these are not the only possible combinations with the National Epic. You could have the Culture GP farm (Hermitage), the Spy GP farm (Scotland Yard) or the Medic GP farm (Red Cross). Those others just didn’t make much sense to me.