"Koko wa dono ataridesuka" means "where is here?" or "which area is here?"

In this sentence, "atari" means "area", "around somewhere",  or "surroundings".

I show some examples.

"Watashi wa kono atari ha kuwashiidesu" means "I'm familiar with this area".

"Kanojo wa atari wo mimawashita" means "She looked around".

"Atari ni ki wo kubarinasai" means "Pay attention to your surroundings".