"Today these teenagers are going to the South."

Translation: Сьогодні ці підлітки їдуть на південь.

[Kapa-_-]

Why на півдні is not correct here

[GeneM.]

Shouldn't до be used here?

[skstudio]

No, it would sound strange. "До" is usually used with places, like школа, магазин, театр..., not with directions.