Palais de la Cite, Paris

 

http://projects.mcah.columbia.edu/medieval-architecture/htm/related/ma_paris_palais_cite_01.htm

France, Paris, Palais de la Cite, plan (after Mesqui): rebuilt c. 1295-1314.

Since this is the historical site for my setting, nice to have a handy reference; I don't have to design the castle myself!

Also, found a cool one in an old French book, page 6: Le Palais de la Cité à Paris, des origines à 1417. Essai topographique et archaelogique. Jean Gerout

(Which was referenced in this JSTOR article: The Doors of the Chapel and the Keys to the Palace of Louis IX

this is nice and plain and simple, from Wikipedia:

https://en.wikipedia.org/wiki/Palais_de_la_Cit%C3%A9#/media/File:Palais.des.rois.Paris.2.png 

Floor plan of the palace as it looked following the construction of Sainte-Chapelle, by Eugène Viollet-le-Duc, with Saint-Chapelle (labeled "A") near the center and the site of the later Conciergerie below it

You know what else is really cool, though? A Reconstitution 3D de la Sainte-Chapelle et du palais royal de la Cité au XIVème siècle.! 

Also, these 3d explorations of medieval Paris: 

Paris au Moyen Age en 3D à vol d'oiseau - Suivez les hirondelles

and this one, at the 5:30-mark... (mostly cool to see the development of Paris as a whole over the centuries, though. Nascimento de Paris medieval 3D

Dragons in Ancient and Medieval literature

244:3, Leaf from choir-book with initial S in red pen-work on green and blue ground depicting a dragon. Netherland. late 12th century, © V&A Museum

https://www.vam.ac.uk/blog/museum-life/here-be-dragons-2 

So, I have a character in 13th century France, who, like his contemporaries, thought dragons were all very well in illuminations and such, (like the above), and for making moral and allegorical points--but as living creatures, they might be considered as exotic, remote, and belonging principally to the past.

Until one shows up in his life. Then he turns to old books for answers. 

 But what would he have found historically? Some interesting stuff, actually, in ancient bestiaries: https://bestiary.ca/beasts/beast262.htm

While the ancient sources included many fanciful details, even as they sought to be factual and comprehensive, their medieval successors had different aims, viewing the genre as an opportunity for making moral observations. Hence the solid association of the dragon with the devil, combining biblical sources with the ancient descriptions in these bestiary entries (such as those found in the Aberdeen Bestiary and many others).
 

For more information, and a fascinating overview article on dragons in the minds of Western peoples across the centuries: 

https://anunexpectedjournal.com/dragons-snakes-and-demons-a-medieval-and-biblical-bestiary-for-modern-minds/

 

Also, I skimmed through this article, which got me tracking in the right direction about bestiaries:

Witty, Francis J. “Medieval Encyclopedias: A Librarian’s View.” The Journal of Library History (1974-1987) 14, no. 3 (1979): 274–96. http://www.jstor.org/stable/25540985.