I should have been more specific, it's a train station mall. And yes, it does have an old-fashioned design, but that's intentional. As I mentioned in one of my posts, the world of Lycoris Radiata will no longer be set in the real world but in a unique alternative version of it.
There are other reasons for this choice, but those would be spoilers.
Oh, and to my knowledge, there are train station malls over a century old inside big cities, such as New York grand central terminal