Is It Sunnah to End Tawaf with Takbir?
Question

Should Tawaf be concluded with Takbir at the Black Stone, just as it starts?
Praise be to Allah.The Standing Committee for Scholarly Research and Ifta’ said:
“Tawaf around the Ka`bah is one of the pure rituals of worship, and the basic principle concerning rituals of worship is that they should be done as prescribed in the Quran and Sunnah. 
It was narrated that the Messenger of Allah (peace and blessings of Allah be upon him) used to say Takbir in Tawaf every time he came in line with the Black Stone. Undoubtedly the worshipper comes in line with the Black Stone at the end of the seventh circuit, so it is Sunnah for him to say Takbir as it is Sunnah for him to do so at the beginning of each circuit, when he comes in line with it – following the example of the Messenger of Allah (peace and blessings of Allah be upon him). He should also touch or kiss the Black Stone if he is able to. 
And Allah is the Source of strength. May Allah send blessings and peace upon our Prophet Muhammad. (Shaykh `Abd Al-`Aziz ibn `Abdullah ibn Baz, Shaykh `Abd Ar-Razzaq Al-`Afifi,  Fatwa Al-Lajnah Ad-Da’imah Lil-Buhuth Al-`Ilmiyyah Wal-Ifta’, 11/224) 
And Allah knows best.