Just a small number of Gaza's residents are granted permission to leave the densely populated 362sq km strip of land that stretches along the Mediterranean, with both Israel and Egypt imposing restrictions on travel and trade.
Israel says it issued 80,000 permits in 2016, for a population of two million. They go to the urgently sick and others with exceptional needs for travel.
But this year the number of permits granted has drastically dropped, according to Gisha, an Israeli organisation that tracks Palestinian freedom of movement issues, with about half as many issued in July than the same month last year. Meanwhile, in recent months the Palestinian Authority has attempted to squeeze Hamas, the Islamist militant movement that rules the strip, by cutting the electricity supply, compounding misery for residents there.
"We thank god we are still living," chirped Samah Lubad, an 11-year-old dressed in a white shirt with a Goofy cartoon print. "You learn to adapt to your surroundings."
The trip took six months to organise, according to Scott Anderson, the West Bank field director for the UN Relief and Works Agency. Just seven of the 91 children had been outside Gaza before, he said.
The children will travel on to the West Bank, where they will stay until the weekend, visiting Palestinian cities including Ramallah and Nablus. Some 38 children from the West Bank visited Gaza as part of the exchange.
With Gaza physically cut off from the West Bank, it will also be the first time most of the children have seen the rest of the Palestinian territories - and for some, relatives who live there.
Israel says it was forced to impose a partial trade and travel blockade on Gaza because of the security threat posed by Hamas, which seized control in 2007 after an armed struggle that followed their electoral win. Israel and the United States consider Hamas a terrorist organisation.
Israeli authorities say Gaza residents could smuggle out contraband for Hamas to use in attacks. Human rights groups argue that the restrictions violate the fundamental right of Palestinians to freedom of movement.
The only other land border, to Egypt, has also largely been closed for the past four years, though it opened for exiting residents for the first time in months last week.
The children all attended UNWRA's summer camp programme, and were interviewed and picked based on their leadership skills.
"I hadn't expected there to be so many entrances," Lubad said of the Dome of the Rock, the site where Muslims believe Mohammed ascended into heaven. "We have a picture of it at home, but in reality it's so huge."
Her friend said it was smaller than she had expected - but was still beautiful. They hurried in as prayers began.
Her family asked her to take photos and to pray at what Muslims call the Haram al-Sharif, or the Noble Sanctuary, the raised esplanade where it is located, alongside the gold-domed Dome of the Rock. Jews call the area Temple Mount, the site of their first and second temples, and the most holy site in Judaism.
Lubad said she had barely slept the previous evening, because she was so excited but also afraid that Israeli soldiers would stop her from crossing.
In the end, the crossing went relatively smoothly, with the children turning up only an hour and a half late for their lunch in the Old City.
Her friend, Lana Meater, though, said she had been afraid though as her impression was that Israeli soldiers were "savages".
Israel withdrew from Gaza in 2005, but Israel and Hamas have fought three wars in the last 10 years, the most recent in 2014, during which more than 1400 Palestinians were killed according to the UN. Israel says it was forced to launch the assault due to Hamas rocket fire.
Before leaving for Ramallah, the children also visited the Church of the Holy Sepulchre, Christianity's holiest shrine and the highlight of the trip for the one Christian Gazan.
"I'm so happy," Hamada Atta al-Masri, 14, said. "The sightseeing, the streets, al-Aqsa. Maybe we'll see it again, maybe we won't. But at least we've seen it."
