MIna

Mina, seven kilometres east of the Masjid al-Haram is where Hajj pilgrims sleep overnight on the 8th, 11th, 12th (and some even on the 13th) of Dhul Hijjah. It contains the Jamarat, the three stone pillars which are pelted by pilgrims as part of the rituals of Hajj.
Mina is referenced in Surah Baqarah in the Quran: “And remember Allah during [specific] numbered days. Then whoever hastens [his departure] in two days – there is no sin upon him; and whoever delays [until the third] – there is no sin upon him – for him who fears Allah . And fear Allah and know that unto Him you will be gathered.” [Surah Baqarah: Ayah 203]
The word Mina means ‘to flow’ as it is here that the blood of sacrificial animals flow during the day of Eidul Adha. During the Farewell Pilgrimage (Hajjat-ul-Wada) the Muslims had brought with them 100 camels to be sacrificed. On the 10th Dhul Hijjah the Prophet (peace and blessings of Allah be on him) stoned the Jamarat and went back to his camp in Mina where he sacrificed 63 of the camels. Ali (may Allah be pleased with him) slaughtered the remaining 37 camels and the Prophet (peace and blessings of Allah be on him) instructed that a part of each camel is cooked and served to him and his Companions.
After the camels had been sacrificed, the Prophet (peace and blessings of Allah be on him) called for a barber to shave his head. Abu Bakr (may Allah be pleased with him) remarked afterwards on the contrast between the Khalid bin Waleed before he embraced Islam (when he was a bitter enemy of the Muslims) and the Khalid who now said, “O Messenger of Allah, they forelock! Give it unto none but me, my father and my mother be thy ransom!” And when the Prophet (peace and blessings of Allah be on him) gave it to him he pressed it reverently against his eyes and lips. It is reported that Khalid bin Waleed (may Allah be pleased with him) used to keep this hair in his headgear.
There lies a cave in Mina known as the ‘Cave of Mursalaat’ as this was where the Prophet (peace and blessings of Allah be on him) was when Surah Mursalaat was revealed to him.
References: The History of Makkah Mukarramah – Dr. Muhammad Ilyas Abdul Ghani, When the Moon Split – Shaikh Safiur-Rahman Mubarakpuri, Men around the Messenger – Khalid Mohammed Khalid, Muhammad – Martin Lings