Question: What number of buildings are still in mecca that were also there in the time of Muhammad?
About the article "Saudi Arabia", section "Islamic heritage sites".

Candidate passages:
The treaty was quite controversial for many reasons.
Originally, the treaty referred to Muhammad as the Messenger of God, but this was unacceptable to the Quraish ambassador Suhayl ibn Amr.
Muhammad compromised, and told his cousin Ali to strike out the wording.
But Ali said, "I will not be the person to rub it out", after which Muhammad himself rubbed out the words.
(, ).
Another point of contention, was that the Muslims objected over a clause of the treaty that said that any citizen from Mecca entering Medina was eligible to be returned to Mecca (if they wanted), while the reverse was not true, and any Muslim from Medina entering Mecca was not eligible to be returned to the Muslims, even if Muhammad himself requested.
()A condition was also placed that the Muslims could not enter for their pilgrimage at that time, but could return the following year.
The treaty also assured a 10-year peace.
After the signing of the treaty, there was still great resentment and fury among the Muslims because they did not like its stipulations.
Muhammad, binding onto the Islamic ethic "fulfill every promise" ordered that Muslims do exactly as the treaty says.
Umar bin Al-Khattab asked improper questions by questioning prophethood, actions and objectives of Muhammad.
Also, many Muslims thereafter objected, when Muhammad told them (thrice) to perform their rites there and then.
()Muhammad insisted that Muslims had been victorious and was supported in this by new revelation: "Verily we have granted thee a manifest victory" (Qur'an 48:1).
He promised much spoils in the near future: "...and He sent down peace of reassurance on them, and hath rewarded them with a near victory, and much booty that they will capture".
(Qur'an 48:18-19)The treaty's stipulations on the movement of persons gave rise to later controversy, when the Quraysh woman Umm Kulthum went to Medina and joined the Muslims, and her brothers demanded her return from Muhammad, as they interpreted the treaty to mean.
Muslim commentator Abdullah Yusuf Ali considers that the treaty had already been violated, probably by an attack by the Quraysh-allied tribe of Banu Bakr upon the Muslim tribe of Banu Khuza'a.
Thus he believed that divine instruction was needed on what was to be done with migrants from Mecca.
Other Muslim sources state that the treaty's restrictions only applied to free men, and not to slaves or women.
Ultimately, Muhammad refused on the basis of revelation from God: "When there come to you believing women refugees, examine and test them... if ye ascertain they are believers, send them not to the unbelievers" (Qur'an 60:10).
If the woman married a Muslim, the Muslims would pay the Meccan refugee's ex-husband a sum equal to the dower he had paid upon marriage to her".
(Qur'an 60:10) 
Following the emigration, the Meccans seized the properties of the Muslim emigrants in Mecca.
Moreover, it was the Quraysh leaders of Mecca who persecuted the newly converted Muslims there, and the latter was compelled to migrate to Medina to avoid persecution, leaving their properties in Mecca.
As opposed to the general belief, Muhammad and the Muslims in Medina found themselves in a more precarious situation than in Mecca.
Mecca offered them the opposition and persecution of the Quraysh while in Medina, apart from the ultimatum of the Quraysh, they had to confront the designs of the hypocrites, and had to be wary of the pagans and Jews also.
The trading caravans of Quraysh, whose usual route was from Mecca to Syria, used to set the neighboring tribes of Medina against the Muslims which posed a great danger to the security of Muslims of Medina given that war was a common affair at that time.
In view of all this, the Quran granted the permission to the persecuted Muslims to take measures in their defense: "Permission to fight is granted to those against whom war is made, because they have been wronged, and God indeed has the power to help them.
They are those who have been driven out of their homes unjustly only because they affirmed: "Our Lord is God"" (Quran ).
The Quran further justifies taking defensive measures by stating that "And if Allah had not repelled some men by others, the earth would have been corrupted.
But Allah is a Lord of Kindness to (His) creatures" (Quran ).
According to Quranic description, war is an abnormal and unenviable way which, when inevitable, should be limited to minimal casualty, and free from any kind of transgression on the part of the believers:Thus, to ensure the security of the Ansars and Muhajirun of Medina, Muhammad resorted to the following measures:  Visiting the neighboring tribes to enter into non-aggression treaty with them to secure Medina from their attacks.
Blocking or intercepting the trading caravans of the Quraysh to compel them into a compromise with the Muslims.
As these trading enterprises were the main strength of the Quraysh, the Islamic Prophet Muhammad employed this strategy to reduce their strength.
Sending small scouting parties to gather intelligence about Quraysh movement, and also to facilitate the evacuation of those Muslims who were still suffering in Mecca and could not migrate to Medina because of their poverty or any other reason.
It is in this connection that the following verse of the Quran was revealed: "And why should you not fight in the cause of Allah and for those who, being weak, are ill-treated (and oppressed)?
Men, women, and children, whose cry is: "Our Lord!
Rescue us from this town, whose people are oppressors; and raise for us from Thee one who will protect; and raise for us from Thee one who will help!""
(Quran ).  
On the eve of the conquest, Abu Sufyan adopted Islam.
When asked by Muhammad, he conceded that the Meccan gods had proved powerless and that there was indeed "no god but Allah", the first part of the Islamic confession of faith.
In turn, Muhammad declared Abu Sufyan's house a sanctuary because he was the present chief, and that all the others were gathered over his territory, therefore: ""Even he Who enters the house of Abu Sufyan will be safe, He who lays down arms will be safe, He who locks his door will be safe"".
He also declared: "Allah has made Mecca a sanctuary since the day He created the Heavens and the Earth, and it will remain a sanctuary by virtue of the sanctity Allah has bestowed on it until the Day of Resurrection.
It (fighting in it) was not made lawful to anyone before me.
Nor will it be made lawful to anyone after me, and it was not made lawful for me except for a short period of time.
Its animals (that can be hunted) should not be chased, nor should its trees be cut, nor its vegetation or grass uprooted, nor its Luqata (most things) picked up except by one who makes a public announcement about it."'
Then, along with his companions Muhammad visited the Kaaba.
The idols were broken and their gods were destroyed.
Thereupon Muhammad recited the following verse from the Quran:""Say, the Truth has come and falsehood gone.
Verily falsehood is bound to vanish.
""()The people assembled at the Kaaba, and Muhammad delivered the following address: ""There is no God but Allah.
He has no associate.
He has made good His promise that He held to his bondman and helped him and defeated all the confederates.
Bear in mind that every claim of privilege, whether that of blood or property is abolished except that of the custody of the Ka'aba and of supplying water to the pilgrims.
Bear in mind that for any one who is slain the blood money is a hundred camels.
People of Quraish, surely God has abolished from you all pride of the time of ignorance and all pride in your ancestry, because all men are descended from Adam, and Adam was made of clay.""
Then Muhammad turning to the people said:"O Quraish, what do you think of the treatment that I should accord you?
"And they said, "Mercy, O Prophet of Allah.
We expect nothing but good from you.
"Thereupon Muhammad declared:"I speak to you in the same words as Yūsuf spoke to his brothers.
This day there is no reproof against you; Go your way, for you are free.
"Muhammad's prestige grew after the surrender of the Meccans.
Emissaries from all over Arabia came to Medina to accept him.
Ten people were ordered to be killed:, Ikrimah ibn Abi-Jahl, Abdullah ibn Saad ibn Abi Sarh, Habbar bin Aswad, Miqyas Subabah Laythi, Huwairath bin Nuqayd, Abdullah Hilal and four women who had been guilty of murder or criticising Mohammed or had sparked off the war and disrupted the peace.
However, they were not all killed; Ikrimah lived to adopt Islam and fight in future battles among Muslim ranks.
Of the two singing girls who were outlawed by Mohammad, one were slain but the other spared because she converted to Islam.
Ibn Abi Sarh had been granted protection under Uthman ibn Affan and when he initially refused to take the mandatory oath of allegiance to Muhammad, the bystanders still did not kill him, much to the regret of Muhammad.
The conquest of Mecca was followed by Battle of Hunayn. 
In 629 CE, Uthman fought in the Battle of Khaybar and later that year, he followed Muhammad to perform Umrah in Mecca.
While in Mecca, he visited his mother and found that his family was not as hostile to Islam as they used to be.
In 630 CE, the Quraysh broke the treaty of Hudaibiyah, and the Muslims attacked and conquered Mecca.
General amnesty was granted to the people of the city, although an exception was made in the case of half a dozen people.
Amongst those not granted amnesty was Abdullah ibn Saad, a foster brother of Uthman.
Later, following an appeal by Abdullah's mother to Uthman, he was forgiven by Muhammad.
Following the Conquest of Mecca Uthman's family converted to Islam and he rejoined his mother and siblings.
Two weeks later, under the command of Muhammad, he participated in the Battle of Hunayn which was followed by the Siege of Ta'if.
To Uthman, the conquest of Mecca and Ta’if were of particular significance, as he had considerable property in both cities, and he could now profitably develop them.
He was also able to set up sub-offices for his businesses at Mecca and Ta’if.
Uthman's wife, and the daughter of Muhammad, Umm Kulthum bint Muhammad, died soon after the conquest of Mecca.
In 630 Muhammad decided to lead an expedition to Tabuk on the Syrian border.
In order to finance the expedition Muhammad invited contributions from his followers.
Uthman made the largest contribution: 1,000 dinars in cash, 1,000 camels for transport, and horses for the cavalry, which Muhammad greatly appreciated.
In 631, along with other Muslims, Uthman moved to Mecca to perform Hajj under Abu Bakr while Muhammad stayed in Medina.
In Mecca Uthman married Umm Saeed Fatima bint Al Walid b Abd Shams, a Qurayshi lady, and returned to Medina with her.
In 632, along with Muhammad, Uthman participated in The Farewell Pilgrimage.
In 632 Muhammad died. 
Once Muhammad and Zayd ibn Harithah were outside the city walls, Muhammad almost collapsed.
They went a short distance outside of the town and stopped in a vineyard that belonged to two Meccans who were there at the time.
The owners of the vineyard had seen Muhammad been persecuted in Mecca and on this occasion they felt some sympathy toward their fellow townsman.
They sent a slave who took Muhammad into his hut, dressed his wounds, and let him rest and recuperate until he felt strong enough to resume his journey across the rough terrain between Ta’if and Mecca.
It was there that the angel Gabriel came to him with the Angel of the Mountains and said that if Muhammad wanted, he would blow the mountains over the people of Ta’if.
Muhammad prayed:The owners also told their Christian slave named Addas from Nineveh to give a tray of grapes to the visitors.
Muhammad took the grape and before putting it into his mouth he recited what has become the Muslim grace: "In the name of God, Ever Gracious, Most Merciful."
(Arabic Bismillah ar-Rahman, ar-Raheem).
Addas became curious and inquired about the identity of Muhammad who presented himself.
The conversation that ensued led Addas to declare his acceptance of Islam, so that Muhammad's journey to Ta’if did not prove entirely fruitless.
He stayed preaching to the common people for 10 days.