Abu has hit the nail on the head here. Atmora, the land that the Nedes invaded Skyrim from (their descendants became the Nords and Imperials) was to the cold North of Tamriel, almost like the Iceland or Scandinavia in our world.
The Mers (Elves) on the other hand, came much earlier from an unfindable continent to the South of the Summerset Isles called Aldmeris - very remeniscent of Atlantis, actuallly. The Almer, the eldest elven race spread throughout Tamriel until the Nedic invasion pushed them back from Skyrim, High Rock (where Aldmeric slaves and Nedics interbred to create the Bretons ... or MenMer as the Nords & Imperials used to call them.)
If you look at Europe from the British Isles down to the Mediterrean Rim including North Africa ... it does have the variety similar to Tamriels mountains, marshes, deserts, jungles, towns, cities, villages, caves, tombs, etc. ....
AND --- this is my own theory -------> the continent of Akivar is very similar to me to Africa. It is to the East of Tamriel and has legendary bizarre creature people. The humanoid Akivaris were wiped out by the SnakePeople. Akavaris have been known to invade Tamriel in the distant past ... doesn't really always specify which Akivar Race. So, my theory is that the Argonians of Black Marsh are descendants of Aldmer and invading Akivari SnakePeople and our beloved Khajiits of Elsweyr (also to the Eastern side of Tamriel) are the mixture of Mer and Akavir TigerDragon bloodlines. Bizarre theory I know, but it is possible and would make sense ... geographically speaking.
Here's a map of my studies from the Imperial Library About this:



Thanks for letting me share my studies ..
