SB 3.21.25
prajapati-sutah samran
manur vikhyata-mangalah
brahmavartam yo ’dhivasan
sasti saptarnavam mahim
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Emperor Svayambhuva Manu, the son of Lord Brahma, who is well known for his righteous acts, has his seat in Brahmavarta and rules over the earth with its seven oceans.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Sometimes it is stated that Brahmavarta is a part of Kuruksetra or that Kuruksetra itself is situated in Brahmavarta, because the demigods are recommended to perform spiritual ritualistic performances in Kuruksetra. But in others’ opinion, Brahmavarta is a place in Brahmaloka, where Svayambhuva ruled. There are many places on the surface of this earth which are also known in the higher planetary systems; we have places on this planet like Vrndavana, Dvaraka and Mathura, but they are also eternally situated in Krsnaloka. There are many similar names on the surface of the earth, and it may be that in the Boar age Svayambhuva Manu ruled this planet, as stated here. The word mangalah is significant. Mangala means one who is elevated in every respect in the opulences of religious performances, ruling power, cleanliness and all other good qualities. Vikhyata means “celebrated.” Svayambhuva Manu was celebrated for all good qualities and opulences.