Above is an image from the official Assassin's Creed 4: Black Flag art book. At one point, it seems the lobby of Abstergo Industries was due to contain the feature wall you can see behind the desk.
Over on the Ubisoft forums, it's being speculated that Ubisoft actually gave us the settings for Assassin's Creed Unity, Assassin's Creed Revelations, and Assassin's Creed 2016 in this image when it was first released back in 2013.
The Santa Maria del Fiore in Florence featured in Assassin’s Creed 2, Notre Dame appeared in Assassin’s Creed: Unity, and the Houses of Parliament will almost certainly star in this year’s release, Assassin’s Creed Victory. We also have a jungle setting, most likely Assassin's Creed 4 itself and the outline of a church, which could refer to either Assassin's Creed 1 or 3, it's too hard to tell from the sliver we can see.
What's perhaps most interesting however, is the final image of the piece, which seems to be a Chinese or Japanese temple. Database entries in Assassin's Creed 4 and images seen at the end of the original Assassin's Creed have pointed to the Land of the Rising Sun as a possible setting for the franchise and the parallels between ninjas and Assassins are strong.
Alex Hutchinson, Assassin's Creed 3 and Far Cry 4's creative director, said last year that an Assassin's Creed game in Japan might be "too familiar". However, in December, Ubisoft's Stephanie Perotti commented,"If we have Assassin's Creed creators that want to spend time [understanding the history of the setting], we can understand Chinese history or Japanese history and make these games about history."
Assassin's Creed Chronicles: China has already been announced and will be available for free to those who purchased the since-axed Assassin's Creed Unity Season Pass. Those who didn't will get the game, but it's not clear when it will be released.
