Research and inspiration maps

So I first researched what inspired my artist, Archibald Knox.

So while researching I found that Knox was really influenced by celtic designs and patterns. I found it hard to find accurate designs or pieces of Celtic work, as I couldn't tell if it was a modern item or actually an authentic Celtic piece

Here is a some of Knox's work. I mainly got images that caught my eye as well as being used for buildings.  

On the picture above I have just written down some thoughts and ideas from Knox's work. 

When searching online I couldn't find really any pictures of Celtic cities, it came up with more villages rather than cities.

So I am thinking about looking at Elven cities for reference, as they would be slightly similar.