Here is all I know about Sérannie, the capital of the Sérannian kingdom. During my 7 years in the fantasy world, I only stayed in Sérannie for a few weeks, but since the country is so centralised, it was impossible not to learn a lot about it anyway...
Here is the place where I'm going to be living now that I'm back in Sérannie. The house of my new ally, Senator Naline. I could certainly have done worse :p
The Sérannian library seems straight from the Roman era, with nobles going there to debate, listen to lectures, practise art and magic, or relax and gossip. It's popular because it serves food and drinks and allows to show off in front of an audience!