Darkan is the rival city to Arkan. Though, it's hard to call them "rivals" when it's so obvious that Arkan is so much better withought even trying.
Interactions between Arkan and DarkanEdit
A battle between The Doctor and the gigantic Hooded-Beaver Matriarch was planned for an episode of Doctor Who, but was cancelled because the residents of Darkan started to protest. It is unclear as to why they wouldn't want this episode to be made, or for that matter why the makers of the show would even listen to them seriously enough to ditch such an episode.
Johnny Depp lived in Arkan until he was about 14 years old, when he was exiled to Darkan for failing out of school. He somehow escaped from there, but he lost his memory of the two towns. He then went on to be a very sucessful actor, in order to fill a longing for the exciting life he could of had as an an Arkvark.
When a baby is brought into a family in Arkan (no matter what mannor this is done) then the baby has to be brought to the beavers. If the beavers do NOT accept the baby into the comunity then it is exiled to Darkan. No one knows what happens to it after that. we can only hope that they are taken good care of and actually raised as a human. But with the Darkan, who knows.
Legend has it that when the first humans came to Arkan, one of them started to misbehave. So they were thrown into the well as the first ever sacrifice. Unfortunately they escaped before the beavers did their once-every-three-weeks sweep of the Social Well to turn the sacrifice into one of them. After escaping, the betrayer went on to found Darkan. Or, so legend says.