Ubisoft level designer Bruno Saint Andre has told Kotaku that Assassin's Creed Unity's representation of Notre Dame has been created on a 1:1 scale.
Paris is the largest city to ever feature in an Assassin's Creed game with the metropolis being larger than all of Black Flag's island landmasses combined.
And creative director Alex Amancio said that each neighbourhood of the city will feel more distinct than in past games in the franchise. One-in-four buildings will feature playable interiors which represents an enormous increase over previous games.
The co-op missions are completely optional and story based, players will be able to complete them alone as well and you'll find them in the game world.
For the first time since 2010's Assassin's Creed Brotherhood, there will be no competitive multiplayer mode.
A much requested feature, a crouch button, has been added.
Another optional activity will be the game's modern day sections starring "you," Ubisoft says this will be different to Black Flag's Abstergo Entertainment segments where you played as an unnamed employee of the Templar controlled company.
Amancio, creative director of Revelations, promised that game's tower defence levels won't be making a return.
Assassin's Creed Unity launches on PC, PS4, and Xbox One on October 28th.