What is National Park and What is its value?
National Park is a 4-tile improvement. It provides Tourism equal to the total value of Appeal for each of the tiles it is built on. The appeal effects can be modified by technology like Computers and Environmentalism civic that each add +25% tourism to all yields. So in this example the park of total appeal of 17, actually produces 25 because of these modifiers.
The World’s first National Park earns +4 Era Score and each subsequent ones +3.
Tourism is essential for cultural victory, so National parks are very valuable in an effort to achieve it. The earlier you start generating tourism, the better. Tourism output from Parks contributes to preventing other civs reaching a cultural victory, threatening your own plans for science or diplomacy type victory, for instance.
Additionally, each National park provides 2 Amenities to the city that owns it and 1 Amenity to the 4 closest cities. These bonuses stack with each park, so if a city owns a park and is close enough to the other two parks, then it would receive a total of +4 amenities.
This could be quite powerful in the game to get your cities to the ecstatic level of happiness, which is achieved with at least +5 amenities per city. Ecstatic level of happiness increases all of the city’s yields by +20% (food, production, gold, etc.). High amenities will play an important role in other types of victories like science or domination, where production is one of the more important factors.
How to build a National Park?
Now that we know that National Park brings quite a bit of benefits, let’s understand how to build it, as it has an interesting criteria list.
First of all you need a Naturalist unit which is purchased with faith.
All tiles must have an Appeal rating of Charming (+2) or better.
The tiles must form a vertical diamond shape.
All four of the tiles must be owned by the same city.
No tile can have an improvement or a District District on it.
The naturalist must be able to stand on one of the tiles to build the Park.
So you need faith to buy Naturalist units who can build parks in the first place. That means you have to consider building Holy Sites and the corresponding buildings: Shrine (+2) and Temple (+4). Holy site is one of the first two districts you can build in the game and if you can get a religion and enhance your faith with other faith-generating beliefs then you should have no trouble accumulating enough of it for multiple Naturalist units later on. Personally, I would plan to save faith for this purpose and use it as soon as Naturalist is unlocked – the earlier you build the parks, the earlier you can generate Tourism and put pressure on the other civs.
It is important to note that each unit costs 600 faith and the cost increases by 100 faith with every new Naturalist produced. Research Conservation civic to unlock Naturalist unit. Note that Canada is the only civ in the game that has Mountie – the unique light cavalry unit that has 2 build charges to construct National Parks. It does not need faith.
Selecting the unit will highlight the eligible Park locations. But how do we know what locations are eligible before we discover Conservation and unlock Naturalist unit?
Here is where the tile appeal analysis comes into play. Remember that the park requires the appeal to be charming or breathtaking, which starts at +2 appeal and can go up as high as 7 or more.
Let’s use the default Appeal lens to view the tiles’ appeal value. All tiles start with a default value of 0 and then are modified by the terrain type.
Mountain and Natural Wonder tiles get Breathtaking +4 appeal by default, so most park locations would be along those types of tiles.
Marches, floodplains and rainforests get -1 appeal by default.
All tiles adjacent to Mountains, Coast, Woods, Oasis or next to rivers and lakes will get +1 appeal. So a rainforest(-1) next to a mountain(+1) and woods(+1) would actually be +1
Sometimes you can identify Park locations right away, other times you might have to give it a bit of thought, because we can increase or decrease the appeal value of a tile by taking certain actions.
How to increase the appeal
Entertainment Complex, Water Park (Seaside resort)
Dam, Canal can mitigate IZ effect
+2: City Park (Liang with Parks/Recreation title), Ice Hockey Rink (Canada),
+1: Château (France), Pairidaeza(Persia), Golf Course (Scotland), Rock-Hewn Church (Ethiopia) or Nazca Line (Nazca city-sate)
Removing improvements: Mine, quarry, oil well/rig
By clearing marches, floodplains and rainforests that carry -1 appeal (adjacent tiles, not the cleared tile)
Conservation civic allows planting of woods using builders (adjacent tiles) – old growth woods gain +1 appeal for the tile they are on.
Reduce the appeal:
Oil Well, Offshore Oil Rig
All Appeal modifiers are cumulative, so the positive ones can add up to a possible +8 for a Breathtaking tile.
Certain civilizations have appeal baked into their traits.
Brazil alters the Appeal of Rainforests in its territory from -1 to +1. Rainforests within their territory can boost Appeal of tiles outside their territory.
America with Bull Moose Teddy grants +1 Appeal to every tile in a city with a National Park.
Australia gains additional yield bonuses from Theater Squares, Holy Sites, Commercial Hubs, and Campuses placed on tiles with high Appeal: +1 for Charming, +3 for Breathtaking.
In addition, there are some Great People and wonders that can boost the Appeal of tiles.
The Eiffel Tower provides a +2 Appeal bonus to every tile in its owner’s territory.
the Golden Gate Bridge provides a +4 Appeal bonus to tiles owned by the city that builds it
Alvar Aalto (GE modern) and Charles Correa (GE information) provide +1 and +2 Appeal bonuses (respectively) to tiles owned by the city in which they use their unique ability