After playing through this fractal twice, I am personally convinced that this area and the cultists are connected to Cantha. More "evidence" I discovered:
1.) The rune on the seals:
Very Canthan/Chinese looking, especially if you compare it with the known Old Canthan ideograms from GW1:
http://wiki.guildwar..._writing_system
I was a bit saddened that there was no exact match, but after showing it to Konig, he theorized that it could be a combination of two or more ideograms.
2.) The Cultist's Hammer:
It's mechanic is rather interesting. It applies stacks of corruption on the player, as well as random conditions, and if someone holds it for too long (around 40 stacks), he or she goes into downed state. However, the Archdiviners can use it without any issues.
Back in GW1 there was a Canthan relic that also worked with corruption.
http://wiki.guildwar...e_of_Corruption
Not the same entirely, but it's worth noting that both works similarly in a way. Applying degenerative effects that could potentially kill someone who resists long enough, or in case the person gives in, he or she becomes a lunatic cultist (many Am Fah suffered that fate before totally succumbing to the Affliction.)
3.) The Petards:
The last trap on the way to the top is a scaffolding that has small, petard-like explosives going off in an orderly fashion. Although it could be just a simple environment design with no further thought behind it, it's worth considering since Cantha is famous for creating explosives both for military purposes and entertainment. Remember all those fireworks and rockets and sparklers from Canthan New Year.
Concerning the Colossus, I believe that while the cultists and the area are the Mist's recreation of a past or future situation in Cantha or south of Cantha, the Colossus itself is a traveler of the Mists just like the players. I have no idea how did such tiny people capture him, though... However, it would be a lot more interesting if the Colossus was a recreation as well. It would mean that we might have a chance at encountering him in the future, and on Tyria.
Edited by Thalador, 30 November 2012 - 01:18 AM.