Make from the station of Ibrahim a place of prayer
Ibne Abul Bashar
The stone upon which Hadrat Ibrahim alaihis Salam stood while rebuilding the Holy Kaaba is known as 'Maqame Ibrahim.' It is a Sunnah to pray two rakats behind this stone after completing Tawaf.
Allah Ta'ala states in the Holy Qur'an:
وَ اتَّخِذُوْا مِنْ مَّقَامِ اِبْرٰهٖمَ مُصَلًّي.
"Make from the station of Ibrahim a place of prayer." - Surah Baqarah (2): 125
According to a hadith, Umar RA mentioned to the Messenger of Allah, peace be upon him, about making the station of Ibrahim a place of prayer. Subsequently, Allah Ta'ala revealed the mentioned verse (Sahih Bukhari, Hadith 402, 4483; Sahih Muslim, Hadith 2399; Jame' Tirmidhi, Hadith 2959, 2960).
During the Farewell Hajj, when the Messenger of Allah performed Tawaf, he stood behind Maqame Ibrahim and prayed two rakats facing the Kaaba, with Maqame Ibrahim positioned between him and the Kaaba (Sahih Bukhari, Hadith 395, 1623, 1627; Sahih Muslim, Hadith 1218, 1234; Jame' Tirmidhi, Hadith 856, 862, 2967).
It is wajib (obligatory) to perform two rakat salah after Tawaf. The ideal practice is to pray these two rakats behind Maqame Ibrahim. If for some reason it is not possible, it can be performed at any place in Masjid Haram. If that is not feasible, then it should be performed inside the Haram area. Performing it outside the Haram area is considered makruh tanzihi (discouraged but not sinful) (See Tafseer of this verse from Ahkamul Qur'an, Jassas; Tafsir Ibn Kathir; Manasik of Mullah Ali Qari, pp. 155-157; Gunyatun Nasik, pp. 116-117; Ilaus Sunan 10/75-81).