Translation of the verse 9 from Surah Al-Fajr : Number of verses 30 - - page 593 - Part 30.
And (with) Thamud (people), who cut (hewed) out rocks in the valley (to make dwellings)?
And [with] Thamud, who carved out the rocks in the valley?
(89:9) And how did He deal with Thamud who hewed out rocks in the valley? *5
*5) "The valley": Wad-il-Qura, where the Thamud carved out dwellings in the mountains, and probably in history they were the first people who started cutting out such buildings into the rocks. (For details, see E.N.'s 57, 59 of AlA'raf, E.N. 45 of Al-Hijr, E.N.'s 95, 99 of Ash-Shu`ara' along with the photographs) .
Source : Al-Fajr Verse 9: And [with] Thamud, who carved out the rocks in the valley?