Khawlah bint Hakim As-Sulaimiyyah (Radiallahu-anha) narrates: I heard Rasulullah (Sallallahu-alaihi-wasallam) saying "Whoever on arrival somewhere says:
أَعُوْذُ بِكَلِمَاتِ اللّهِ التَّامّـَاتِ مِنْ شَرِّ مَا خَلَقَ
I seek refuge in Allah's perfect words from the evil of what He has created
Then no evil shall befall him, until he departs from where he arrived"
(Muslim)