Good Deed: #334 When ascending or descending
Narrated by Jabir bin ‘Abdullah (May Allah be pleased with him) reported:
When we ascended (a height) we would proclaim: “Allahu Akbar (Allah is Greatest),” and when we descended (from the height) we would proclaim: “Subhan Allah (Allah is free from imperfection).”‘
[Al-Bukhari].(Riyad-us-Saliheen Chapter 171 Hadith 975)(Bukhari Volume 4, Book 52, Number 236)