Domes! They aren't great. Focus too much on them like the AI does and you'll be domed for all eternety. They cost too much and take up space where you could put something else. So how do you make them good without making them too good? By having situational bonuses!
Domes cost 2 energy (one less with biospheres) and give 2 culture. And that 10 hitpoints that I can't imagine ever being a key factor for a human player.
So with this, the dome gets an extra 1 culture if it is:
Next to a city,
On a hill,
On the coast,
Has fresh water i.e. a lake or river.
Basically the better it is to live on that tile the better the dome is. Nice mountaintop view of the ocean with a lake on the other side and the city close by for a short commute. That's dome life. 6 culture! Not a tile you'll get often though.
I've also included part of Artificial Unintelligence Lite by Delnar_Ersike. Specifically the part that reduces the AI's love of culture. The AI loves their domes and terrascapes and if I didn't lessen that while making domes better they'd never build anything else.
A dome that is giving 5 culture will show a 9 on the tile, but it is generating the correct amount.
Domed Life 2016-10-05