National Parks can be built on a cluster of any four contiguous hexes that meet the following requirements:
- The tiles must be Natural Wonders, Mountains, or a tile with an Appeal of Charming or better.
- All four of the tiles must be owned by the same city.
- The tiles must form a diamond shape.
- No tile can have an improvement or a district on it.
A National Park's Tourism output is equal to the total Appeal of all the tiles included in the park.
Creating a National Park will also give your civilization extra Amenities. You will receive 2 Amenities in the city that owns the park and 1 Amenity towards the 4 closest cities in your empire.