There are 14 National Wonders. The series consists of the following four parts:
I. Click here for National Wonder #1: Flop 3
II. Click here for National Wonder #2: Top 3
III. Click here for National Wonder #3: Good. Basic. Not Game Breaking.
IV. Specific. Key for some scenarios.
Hermitage
Cost: 300 (Double Production Speed with Marble)
Effects: +100% in this city; +1 Great Artist
Requires technology Nationalism
The first is in some teamer games when the game is decided by a point race - not exactly something that the Hermitage can be proud of (if it is capable of being proud in the first place ).
The second is the obvious one, Culture Victory. This win condition is one of the most exotic parts of civ. I´ve seen it done in multiplayer games and not only in very exotic setups. Clan [RUS] for instance won a CCC Ironman this way (sorry for not remembering the actual player ). As things are Culture Victory is a very rare occurence in multiplayer right now. Whenever though you try achieving one, no matter whether multi or single player, you´ll want the Hermitage. Otherwise not. That´s probably the definition of "specific use".
Heroic Epic
Cost: 200 (Double Production Speed with Marble)
Effects: +100% military unit production in this city; +4 ; +1 Great Artist
Can only be built on Renaissance and earlier starts
Requires technology Literature, Barracks, a unit of level 4 experience
In general you get the Heroic Epic into a non-capital city and use a couple of mines to produce one unit (in teamers most of the time Knight)t per turn. The bonus applies to slaving as well, but it´s pretty easy to set up a city with it and Forge and just get one Knight per turn anyway with working a couple of production tiles.
Globe Theatre
Cost: 300
Effects: No from this city; +6 ; +1 Great Artist
Can turn 3 citizens into artists
Requires technology Drama and X theatres (X depending on map size)
First being One City Challenge games. In those you want to grow your one city as much as the available food allows. Happiness is a limiting factor here and Globe Theatre is the best way of handling that. It is impossible to win any of the common (and as far as I know all of the uncommon ) setups of OCC games without Globe Theatre.
Second being Ironman/ffa games where you want to keep a certain city (mostly the capital and sometimes a GP city) at as much population as possible but don´t have access to enough happiness (resources, religion etc.), yet don´t won´t to run Hereditary Rule (anymore). Usually you don´t want to research Drama at all. With average land and some good strategical decisions you´ll be able to handle your unhappiness anyway, but in case you get stuck with a bad happiness situation, this is the way to go, especially if you at least have Dye and can use Theatres for another happiness in any city that needs it.
National Park
Cost: 300
Effects: +1 free specialist for each worked forest preserve in this city; No in this city from pop; +3 ; +1 Great Scientist; Removes access to coal for this city
Requires technology Biology
First there are Modern and Future Start games where cities start with population 5 and grow fast due to Biology being available from the start and hence farms being more effective. Unhealth becomes an issue here very fast and cities not planted next to fresh water get in trouble quick. National Park can be build into a big city working lots of tiles in order to make that city even more productive and use it for spamming (expensive) settlers for the whole team for example. Optionally the Park can be build into a city with huge unhealth struggling at getting one unit per turn.
In OCC games basically the same is true that is true for the Globe Theatre. I´m no OCC expert though and am not sure what is going on there currently in for example Ancient start, where cottaging all forests was an option as well I think - but I have no clue . Anyway the National Park is used heavily and just even more true than for Globe Theatre you cannot win for example a Renaissance Start OCC without getting it as quick as possible - here more than with Globe every turn counts.
Third if for some reason (hopefully not related to mistakes you might have made so far ) in an Ironman/ffa if at the time you get access to National Park and still have a spot for a city (potentially in freshly conquered land of an underdeveloped opponent?), you can put National Park in there. It´s more a question of micromanaging out the best possible way, not do-or-die though. If you´re running Representation for some reason and plan on keeping doing so, the Park gets much stronger in that late phase due to a decent research output, otherwise it´s pretty negligible since you probably have another GP city (with wonders in it) that is doing the GP work anyway.
Recommended Related Articles
For articles "National Wonder #1 - #3" see the links at the beginning of the text.
Explanations to the concept of the "Happiness Cap", explaining how the available happiness providing aspects influence the way you can develop your empire.
Introduction into modern and future era starts. How to handle early buildup, what to watch out for while planting, also in relation to health issues, how to determine the long-term strategy etc.
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