Place name were swamyambhu Manu first lived and were his son king uttanpada established his kingdom?
According to Manu Smriti 2.17-19.:
The land created by the gods and lying between the divine rivers Saraswati and Drishadwati is called 'Brahmavarta' - the region of Brahman. The conduct handed down from generation to generation among the social classes and the intermediate classes of that land is called the 'conduct of good people'. Kuruksetra and the lands of the Matsyas, Pancalas, and Surasenakas constitute the 'land of Brahmin seers', which borders on the Brahmavarta. All the people on earth should learn their respective practices from a Brahmin born in that land.
I hope this clarifies your queries.