SARJAH, Syria -- Abdulkader Darwish did not go far after a Syrian military aircraft dropped a bomb near his house last year, prompting him to gather his family and flee. He ventured with a shovel into the local olive groves. There he dug through the sealed entrance to an abandoned Roman cave.
Nine months on, dozens of members of the extended Darwish family have passed a cycle of the seasons crowded together in the damp and almost unlighted space. They have gained neighbors all the while, residents of a subterranean community in Syria's northwest.
"There are many caves here, a line of caves, like an ancient village," Mr. Darwish said as he huddled with several children inside. "All of them have been cleaned and are now occupied. There is not a vacant cave."
As the bloody civil war between the government of President Bashar al-Assad and the opposition enters its third year, and Mr. Assad's military continues to pound neighborhoods aligned with the rebels, uncountable Syrian families are waiting out the violence in the caves of bygone times. They are part of the four million people who the United Nations estimates have been forced by the war from their homes, a displacement that seemingly grows each week.
They live a grim existence -- a routine of trying to eat, to stay warm and dry, to gather firewood and water out in the elements, all while listening for the sounds of incoming planes and artillery shells.
Explanations of the origins of these underground shelters, many of which are set among other Roman ruins, vary from squatter to squatter. Some say they once were pens for livestock. Others say they were temporary quarters, occupied while more impressive dwellings were built in the centuries before Jesus. Perhaps some were crypts.
Whatever the intention of those who first dug them, Syria's caves have become essential once more, restored to modern use because their thick walls offer a chance of survival to a population under fire.
Villagers in Idlib Province talk of tens of thousands of people living this way. While these numbers are unverifiable, there are signs that cave demand exceeds cave supply, as more people lose their homes or take flight.
"This was the only cave I could find when I came here," said Ahmed Sheikh, 51, whose family lives in a smaller cave than the Darwish family's four-room warren, and slightly farther uphill.
In other towns across the province, part of the population remains at home. In those places, some families rely on caves only as temporary bomb shelters, places to rush to during danger. Their shelters vary from holes freshly chipped under stone ledges to deep basementlike rooms, known as beli, where food and animal feed would normally be stored beneath a villager's home.
For those lucky enough to have them, the temporary shelters can be stocked with hanging kerosene lamps, blankets and bedrolls, offering families a place to pass the most dangerous hours or nights.
But in many villages, as in Sarjah, which the government has punished with what seems a special fury, the dangers are of a different order. People have moved from village centers into rural caves full-time. They have no plans to leave until Mr. Assad's military is weakened to the point that its ordnance can no longer regularly reach their former neighborhoods.
"It became impossible to live in the village without being exposed to the possibility of your death at any time," Mr. Sheikh said.
He spent 35 days improving his cave after claiming it last summer. He installed a wood-burning box stove, cut a ventilation hole, dug and hauled away mud, and hung heavy blankets to reduce drafts and create one area warmer than the rest.
His family is fastidious. The warmest room is neat, and shoes are stacked at its edge. "I keep it organized," he said.
Cleanliness alone cannot keep away the hardship. After enduring the winter, he said, his wife's legs are swollen. Their three young children suffer from chest infections and earaches.
As he spoke, a sluggish black beetle, about the half the size of his thumb, slid off the wall and came to rest on its back beside his feet.
Mr. Sheikh picked up the insect and threw it toward the cave's entrance, like a stone.
"Now you have seen with your own eyes how we are forced to live," he said.
Artillery boomed intermittently from a brick factory that Mr. Assad's army occupies on the lowlands of Idlib's plain. Soldiers were firing into the mountain towns, seats of the armed opposition that have given rise to well-known rebel commanders.
Twenty-five members of Mr. Sheikh's extended family have been killed, he said, most of them by this kind of shelling, a few while in battle at the front lines.
"Our situation is like the man who is lost at sea," he said. "He finds a stick and holds onto it as long as he can. But we have lost 25 people already. If the situation continues, you will not find anyone in the entire Sheikh family."
Another inhabitant of one of Sarjah's many caves, Ibrahim Haj Musa, 50, stood near a damp stone column in the darkness and vented his disgust at the outside world, blaming the United Nations and the West for doing little to alleviate Syria's suffering. As is common in Syria, he said that when Western governments withhold weapons from the opposition and send in only limited aid, they are essentially collaborating with Iran, Russia and China in the destruction of Syria.
"And then they invite us to the Friends of Syria conferences," he said, of the French- and American-led multilateral group that has vowed to support the Syrian opposition. "What kinds of friends are these?"
At the entrance to the first cave, Ahmed, 15, one of Mr. Darwish's sons, had chiseled an Arabic word into the slab of stone above the cave's door. His work had given their cave a name. "Home," the inscription read.
Mr. Darwish spoke of the label with resignation. "Animals, like wolves, refuse to live in such places," he said. "But we have to accept this."
Uphill, rocks had been stacked to form the walls of a small outhouse. A hanging blanket served as its door, concealing an open trench.
Farther on, past another cave from which several children peered out, Aziza Sheikh, one of Mr. Sheikh's relatives, draped laundry over a rope in the open air.
Inside the cave, Yousef Sheikh, 5 months old, slept in a tiny hammock. His mother had spent the last months of her pregnancy in this cave, and left the cave to deliver the infant in an aid station, Ms. Sheikh said.
She returned with the infant hours after his birth, Ms. Sheikh said, and was raising her baby here, beneath the ground.
This article originally appeared in The New York Times.