Question:

What is the ruling, if after the prayer it becomes clear that it was prayed towards other than the direction of the Qiblah; does it make any difference if this (happened) in a Muslim land or a kaafir land or in the wilderness?

Answer:

If a Muslim is on a journey or in a land in which it is not easy to find someone to show him the Qiblah, then his prayer is correct even after it becomes clear to him that he did not pray towards the Qibla. But if he was in a Muslim land, his prayer is not correct, because he is able to ask someone to show him the direction of the Qibla, just as he is able to know the direction of the Qibla via the mosques. [Fataawaa Muhimma Tata-allaqu Bis-Salaah: Imaam Abdul Azeez Bin Baaz (rahimahullaah): page:5]