It is narrated from Sayyidah Khawlah bint Hakim (may Allah be pleased with her) that she heard the Messenger of Allah (peace and blessings be upon him) say: "When one of you stops at a place, let him say: 'A'udhu bi-kalimatillahit-tammati min sharri ma khalaq' (I seek refuge in the perfect words of Allah from the evil of what He has created), for nothing will harm him until he departs from there."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20974