Question about requirements for building a library

[xrys]

Can libraries only be built in cities?
The civilopedia does not list any requirements when I look at the 'Library' entry.

I could have sworn that I could purchase them for a town, but that might be faulty ADHD memory on my part.

[RamboRusina]

Yes, libraries are for cities only. Augustus can buy culture buildings in towns that you might be mixing things up with.

[TheNightglow]

all science, culture and eco buildings can by default only be build or purchased in cities, however there are some effects and abilities that can unlock certain buildings for towns as well

like augustus is allowed to buy any cultural building in cities
i dont know if there is something like that for libraries aswell tho