This is a story of Prophet Saalih (alaihi wasalaam) and his people known as Thamood. His story is interesting because Allah does not just tell it once in the Quran, but many times. Every Muslim knows the story about the she-camel.
The lessons from this story are many: Not putting Allah to test, or disobeying Allah. Also it tells how many people will agree with & follow Allah when things are going good, but then go back on what they have promised to Him, turning back to our previous ways.