A dozen steps separate the horrors of the daily shelling from an oasis of peace, an underground refuge where volunteers have set up what they say is now the only school in the eastern Syrian city of Deir Ezzor.
After months of heavy fighting between rebels and troops of President Bashar al-Assad, the eastern oil hub on the banks of the Euphrates River is in ruins, its homes bombed and its streets littered with rubble and broken glass.
Deir Ezzor was once home to around 750,000 people, but the combat and the thud of bombs and mortar rounds has driven more than half a million to flee, including most of its teachers.
Worse than the shortage of materials here, with old, dog-eared textbooks having to be shared, is the lack of qualified teachers.
Yasser Tareq is one of the founders of the school in the Al-Omal neighbourhood, which offers classes six days a week to an average of 50 children from across the city.
"Most of the teachers have fled, and very few people volunteer to help us with the classes because they are afraid," added Tareq, who was formerly chief of security for the area's oil wells.
And that fear, combined with common sense, dictates how the school operates.
"Our classes are held in the evening, because it is much more dangerous in the day time," Tareq explained. "The shelling is appreciably less intense then, and it is safer for the children to come to school."
As the evening progresses into the night, and the children have been fed dinner, perhaps had a minor ailment treated and are ready to go home, "we make them leave one by one to avoid a bomb or a regime sniper hitting a whole group of them."
But the shelling never completely stops, and "when they start to bomb, the children are terrified," said Beda al-Hassan, the school's principal.
"So what we do is sing songs with them and clap to the beat. Eventually we get them focused on the music and they forget about the bombs," she explained.
"This isn't the sort of life children should have. None of this is their fault, but they are the ones suffering the most."
Tareq said the "idea is that this school helps the children to forget for awhile what's going on when they leave here; that there is more to life than the bombing and war that is devastating the city."
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And it helps.
Twelve-year-old Sultan Mussa said: "I come to school every day because I love studying. I can do something different here."
Before the school opened in September "I spent the whole day closed up at home because my parents were afraid of the bombing and wouldn't let me go out."
Ten-year-old Sidra said she liked coming to school "because I can play here. "My house was bombed and I lost all my toys."
Sidra said she lost five of her cousins when they were hit by a mortar bomb.
"After that, my parents shut me up in the house, but they found out that other children in the neighbourhood were coming to the school, and now I come every day with my two sisters."
Education is central, with the curriculum running from English to mathematics, from Arabic to religion, but recreation is also important.
Tareq even says, tongue in cheek, "this isn't really a school, it's a playground."
And there actually is a playground, though the dangers of war mean it can't be out in the open air.
Located underground in another building in the neighbourhood for security reasons, it has been fitted with a ping-pong table, chess boards and a video player that shows Tom and Jerry cartoons.
Principal Hassan's five-year-old son Qutaiba is one of the pupils, and says as he scoots around on a toy motorcycle: "I can't wait for school to end and for play time to begin."
In the end, Tareq is proud of what he and the others have managed to do here.
"This place was unimaginable a few months ago because of the intensity of the bombing," he said. Now, "just for a second, we have succeeded in getting them to forget" the hell outside.