"Belok ke arah mana?"

Translation: Turn to which direction?

[dkfour]

"turn which way" is a better translation

[glhaynes90]

The equivalent sentence in English would be "Turn which direction?" or "Turn in which direction?"

[gilscot1]

You can understand the English translation, but it's not English. A native speaker would express that meaning in lots of different ways - not helpful for non-English speakers! eg Which way do I go? Which turning should I take? Which direction should/do I take? Which way? That's a real difference between Indonesian and English - Indonesian says the basic meaning, and English finds lots of ways of dressing up that meaning!