Fatimah (may Allah be pleased with her) used to visit the grave of her uncle Hamzah every Friday, and visiting graves being Sunnah

Sayyiduna Ali bin al-Husayn narrates from his father (Sayyiduna al-Husayn, may Allah be pleased with him) that Sayyidah Fatimah (may Allah be pleased with her), the daughter of the Prophet (peace and blessings be upon him), used to visit the grave of her uncle Sayyiduna Hamzah (may Allah be pleased with him) every Friday; she would pray there and weep.
All the narrators of this hadith are trustworthy. I have made a thorough effort in encouraging the visiting of graves, so as to gain the reward of taking part in it, and so that one who is miserly about his religion may know that it is an established Sunnah. May Allah Almighty send blessings upon Muhammad (peace and blessings be upon him) and all his family.

Sayyiduna Anas (may Allah be pleased with him) narrates: I was sitting with the Prophet (peace and blessings be upon him) when a funeral passed by. He (peace and blessings be upon him) asked: "Whose funeral is this?" The people said that it was the funeral of so-and-so; he loved Allah and His Messenger, did deeds of obedience to Allah and strove in them. He (peace and blessings be upon him) said: "It has become due, it has become due, it has become due." Then another funeral passed by, and he (peace and blessings be upon him) asked: "Whose is this?" The people said: It is so-and-so's; he hated Allah and His Messenger, did deeds of disobedience to Allah and strove in them. He (peace and blessings be upon him) said: "It has become due, it has become due, it has become due." The people said: O Messenger of Allah, your statement about this funeral and its praise: the first was praised with good and the second with evil, yet you said for both: "It has become due, it has become due, it has become due"! He (peace and blessings be upon him) said: "Yes, O Abu Bakr! Allah has certain angels who speak on the tongues of the children of Adam about the good or evil of a person (that is in him)."
This hadith is sahih (authentic) on the condition of Muslim, but they did not record it with this wording.