KUBAN'

Seems that Cuba and Kuban' indeed may be cognates.

The Cuba story claiming the island's name means 'earth' in Kartvelian, was already told.

But why wouldn't Kuban' bear the same root? In fact, "Кубань" (or, more exactly, "Кубанi", since the soft sign, as we know, stands for an ex-vowel) is a pure Kartvelian adjective derived from the CUBA noun. So, 'kubani' translates from Old Kartvelian as 'earthy'.

Now let's have a look if Kuban' has anything to do with earth. The question is stupid, since every child knows that Kuban's main treasure is the black earth, 'chernozem'. Here's what Kuban' people themselves say about it:

'Chernozem occupies most part of our region and is our main treasure'.
http://kuban-moi-region.ru/chernozemy-pochvy.html

So, Kuban' in Kartvelian means 'earthy land'.