The floodplane

...I'm sorry. I couldn't resist the pun.
I am rubbish at the Cyrillic alphabet, but points to whoever spots the joke despite that.
World two:
The floods come frequently, and without warning. Water rises swiftly to cover the land, leaving above water only the peaks of the great mountains that dot the landscape. It is not really known how humans evolved in such an environment, but the leading theory is that the floods started only recently (geologically speaking) - a punishment from an angry God.
Regardless, the floods have been happening since the beginning of recorded history, and society has been shaped by them. In the east, lie the squabbling kingdoms of Deed Tseg. The kings there build great stone castles upon the mountaintops, and rule with an iron fist. Open rebellion is unthinkable - a seige takes time, and to be barred from the castle when the floods come is a death sentence.
To the north, there (sometimes) live the Khôwôlt traders, in truth the great power of the known world. It is tradition that all Khôwôlti children be born on a boat, and many of them will spend most of their lives in one, travelling from place to place, buying and selling. It is a profitable business, since travel is nearly impossible for the average person. Khôwôlt boats are specially designed to act as land vehicles when the floods are not come, propelled slowly by dwarven engines. But the great achievement of the Khôwôlt is their great floating cities, which rise with the floodwaters - the sceret of which, they jealously guard from outsiders.
To the South and West, there lie a mix of different nations, which cannot be summed up with a brief description, and might therefore prove useful if a story required a specific kind of country *cough*. What these nations have in common, though, is the cult of Ursgal, dedicated to the worship of the beings responsible for the floods. Indeed, many of them tend to be functionally theocracies, under the cult, and a few practise ritual drowning as a form of sacrifice. Having been beaten back several times by great armies of Ursgal cultists, few of the kingdoms of Deed Tseg have any dealings with Ursgal nations, but Khôwôlti traders often travel them extensively - and some even speak of strange lands beyond.
And finally, wherever there is space for them, there are the dwarves. Starting at the mountaintop, the dwarves dig their fortresses deep into the mountain's rock. They dig so carefully, and reenforce their homes so well, that not a single drop of water can get in when the floods come. Since they take up so little space, their territory often overlaps with that of human nations - indeed, to have a dwarven fortress below one's mountain is often considered a great honour. Dwarves have their own cultures and clans, alliances and emnities, but humans know very little of such things.