'The Old Country' is a euphemism for a large continent (think Africa) that used to be a thriving series of smaller countries (think Egypt), that gradually fell into chaos and bickering and hasn't really technologically advanced in hundreds of years (think the African warlords.)

Despite this, there are great interests in archaeology in the Old Country (again, think Egypt) - many ancient tombs, dungeons, and other places remain undiscovered, unexplored, or unexploited.

Nyx was apparently some sort of hedge wizard back when magics were more heavily regulated, taught only by obscure colleges, and regarded with a certain air of mystique, and was apparently important - or wealthy - enough to afford his own tomb despite being an apostate. The place might be unstable, and probably wasn't up to ancient dwarven standards and codes. Judging by what they saw, the furnishing is old Narthwellian in nature, which would put it at somewhere between 860 and 1040 years ago. (Translation: likely around Renaissance era.)