On the roof of a ruined hotel-turned-observation post nicknamed "the Ramadi Inn," two U.S. snipers listen to Johnny Cash's "Ring of Fire" on an iPod and watch a firefight through holes knocked out of a penthouse wall.

Marines at another sandbagged outpost up the road are firing grenades at insurgents, sending clouds of smoke rising above a hazy midday skyline of rusting water towers, minarets and an exquisite blue-domed mosque.

"It's a never-ending war," says one of the snipers, 22-year-old Spc. Jarrod York of Mansfield, Pa., as explosions boom in the distance.

Ramadi, populated by Sunni Arabs 70 miles west of Baghdad, is the most dangerous city in Iraq for U.S. forces. Commanders say there are more insurgent attacks here than anywhere else in the country, with militants and American troops exchanging fire several times a day — at least.

American troops seized "the Ramadi Inn," known officially as OP Hotel, in 2004 to protect a road through the heart of the city. Two years later, they are using the building and others like it to secure Route Michigan, a key supply road for U.S. forces.

CountryWatch: Iraq

This four-story structure is one of the tallest in town, offering panoramic views over an urban wasteland crawling with insurgents. The troops say the militants are also watching them — casing their positions in vehicles, peeking around corners, looking from afar through binoculars and video cameras.

It's difficult to imagine the hotel ever had a place in Ramadi's hospitality industry. Rocket blasts have pummeled the building, a truck bomb nearly destroyed it and human hands have stripped it bare of furnishings.

The rooms on one dusty, darkened floor have been converted into sandbagged machine-gun nests manned by U.S. and Iraqi forces.

With boxes of ammunition and spent bullet casings at their feet, troops sit with binoculars 24 hours a day. They brace for attacks, watch for guerrillas and keep an eye out for battles — muzzle-flashes, explosions, plumes of smoke.

"We watch for anything that's not normal. But nothing's normal around this place," said Spc. Joe Sommer, 20, of Lawrenceville, Ga., his belt-fed machine-gun poking out a hallway window.

Past dreary halls draped with camouflage nets, soldiers sleep in cot-crammed quarters with no electricity, running water, phones or Internet.

Iraqi forces arrived a couple weeks ago and sleep on their own floor. A few promptly installed a satellite on the roof so they could watch TV in their rooms.

Every window has been sealed with leaking sandbags. Troops joke the weight of the bags may bring down the building. Scrawled on one wall: "Ramadi Inn, aka OP Sandbag."

Only a few rooms have generator-driven fluorescent lights: the command center and a kitchen stacked with military rations. A few rays of sunlight stream in during the day, but the darkness "makes you feel like you're living in a cave," said Army Lt. Nicholas Goshen, 24, of Cleveland.

Ringed by trash, blast walls and razor wire, the hotel's crumbling brown balconies and boarded windows are covered by chicken-wire fencing that hangs from the roof to help deflect shoulder-fired grenades.

Exchanges of fire have wasted most surrounding buildings and forced nearby residents to flee.

"It's sad, but this hotel is critical to keeping Route Michigan open," Goshen said, looking at vacant, bullet-sprayed shops across the street.

The snipers are stationed in a small enclosed room called the penthouse, which is on the roof.

Sgt. 1st Class Britt Ruble, platoon commander for Charlie Company of the Army's 1st Battalion, 506th Infantry Regiment, said snipers had "taken out quite a few people digging in alleys" — planting roadside bombs — in the past year.

Ruble said rocket-propelled grenades struck the hotel at least 10 times in recent months, one of which hit the wall above Spc. Richard Cruz, 27, of Los Angeles.

"It knocked him back off his gun, but he got right back up and kept shooting," Ruble said.

Soldiers said bullets flew through the windows during that gunbattle in March, ricocheting off walls. One round hit an American soldier in the ankle; a medic found the 7.62 mm slug in his boot.

After that, "we took the sandbags all the way to the ceiling, doubled 'em, made 'em so we can actually fight from 'em," Ruble said.

Black marks and chips on the walls and ceilings bear testament to such stories, but soldiers say it is quieter here now than it had been — and quieter than other Marine-manned outposts along Michigan that are attacked daily.

When not on guard duty, troops read, play hand-held video games or write letters. On Sunday, a few watched "The Greatest Wrestling Stars of the 80s" on a laptop. Hot meals arrive in plastic containers once a day. Sometimes breakfast and even ice cream are thrown in.

But luxury it is not.

On some walls the words "never forgotten" are written beside the names of fallen soldiers.

Goshen said he tries to call his girlfriend before going on a four-day stint at the hotel. This time, coming off another mission, he had no time.

"She knows I'm guarding a hotel, but she probably thinks it's a nice hotel and I live in a room. She doesn't understand," he said. "My family would probably get a little scared if they saw what this place looks like."