By Martin Patience
BBC News, al-Amari refugee camp, West Bank
As you wind your way through the tight alleyways of the al-Amari refugee camp it's almost impossible not to rub your jacket against the dirty walls.
The sun barely reaches these parts of the camp, which echo with sound of young children playing.
Khamees was born in a village, now in Israel, that no longer exists
But it's in alleyways like these across the Middle East that one of the thorniest issue of the Israeli-Palestinian conflict lies - the Palestinian refugees and their "right of return".
Arab leaders currently holding a summit in the Saudi capital, Riyadh, have urged Israel to accept an Arab peace initiative first proposed in 2002.
Under the plan, Arab nations would recognise Israel if it withdraws from all land occupied in the 1967.
The plan demands the establishment of a Palestinian state and also calls for a "just solution to the Palestinian refugee problem", based on people returning to their homes or the payment of appropriate compensation.
But how many Palestinian refugees would be expected to return to what is now Israel is not clear.
According to the United Nations, 750,000 Palestinians fled from or were forced to leave homes and land that is now located inside Israel. When Israel was established in 1948, the neighbouring Arab countries invaded the young state leading to a refugee crisis.
Including descendants of these people, there are now 4,375,050 Palestinians registered as refugees with the UN.
Khamees Sayyid Ahmed has lived in the al-Amari refugee camp for almost 60 years.
Sitting in his bare-walled home, an electrical heater is positioned at his feet, a single bar glowing red with heat.
The 76-year-old's story is characteristic of many of Palestinian refugees from the period.
Sea of tents
Mr Ahmed says that he grew up on a small holding in a village called Nana, now destroyed, located close to the Israeli town of Ramleh.
The family owned several acres of land where they grazed cows, sheep and goats. They also grew tomatoes.
When he first arrived in al-Amari refugee camp he says that there was just sea of tents.
By the 1970s, the family was living in the four-room house that they currently reside in.
But despite the permanence of the houses - the tents went decades ago - Mr Ahmed insists he would return to his land inside Israel immediately.
"If Israel gives me a tent I would go back to my land tomorrow," he says.
Zeinab, his wife, is from the same village. She says that they would unwilling to accept any form of compensation for the lost land.
"They could fill this house with gold and I still wouldn't accept it," she says.
'Right of return'
For most Palestinians - still without a state - this is an issue that they continue to cling to.
A survey conducted by the Palestinian Centre for Policy and Survey Research published in 2003 stated that more than 95% of the refugees they interviewed insisted on maintaining the "right of return".
But it is unlikely most of the refugees would exercise the right if given the choice, insists says Mahdi Abdul Hadi, chairman of the Palestinian Academic Society for International Affairs in East Jerusalem.
"The right of return is a huge taboo, no Palestinian will break it," he says. "For us the right of return represents our memory, our heritage, our culture.
"When we Palestinians insist on the right of return, it's us saying to the Israelis that you cannot strip of us everything."
But for most Israelis, Palestinian refugees returning to land which is now inside Israel is a non-starter.
If all the refugees were to return to Israel, there would cease to be a Jewish majority in the Jewish state.
But Mr Ahmed and his wife are unmoved by this.
"I remember my village like I remember that I need to pray," says Zeinab. "I will never forget my village."
As Zeinab speaks, one of her 15 children, Youssef, gently nods in agreement.
For many Palestinians, this is an issue - like the rusty key to their old home that hangs from a hook in the Sayyid Ahmeds' living room - that will passed on from generation to generation unless a solution is reached.
"I feel the same way as my parents," says 35-year-old Youssef. "I want to return to my land."