At first glance, the carpark beneath Rambam Medical Centre in Israel’s north doesn’t look particularly remarkable – three levels of subterranean car spaces, painted lane markers and speed humps, all of which can be found in parking lots everywhere.

What’s different at Rambam lies in the walls and ceilings, piped as they are with oxygen and suction lines, data sockets and a capability for industrial-scale cooling – the essentials required to operate a functioning hospital beneath the ground.

“Basically it’s a hospital converted into a carpark,” said Dr Avi Weissman, deputy director at Rambam.

“We said in peacetime we’ll use it as a parking garage, so you solve two problems.”

Last Thursday, as Israel launched pre-emptive strikes against Iran’s growing nuclear capabilities, staff at the hospital commenced a 15-hour conversion of the parking lot to bring it up to a war footing, removing hundreds of vehicles, sterilising each floor, and transferring pallets of equipment and medication along with about 700 patients.

Up to 2000 beds can be protected here from the incoming missiles raining above, be they ballistic, chemical or biological in threat, Dr Weissman said. Should the facility seal its doors in the event of a catastrophe, stores of oxygen, gas and solar power are available to keep it running for an entire week.

“It’s not protected against an atomic bomb, but I guess it doesn’t matter where you are if it’s an atomic bomb,” he conceded.

Built in 2014 as an answer to the threat of rocket fire, its first real test came a year ago during Israel’s war against Hezbollah, when incoming rockets were launched sometimes hourly towards Haifa and surrounding cities of the north.

Today’s conflict with Iran, involving barrages of hypersonic missiles, provides a new test for the facility and its patients.

“We’re getting a good use out of it unfortunately,” Dr Weissman said.

Buzzing with staff and organised to resemble an actual hospital, its three floors have been arranged into sections like nephrology, internal medicine, pediatrics, and even a maternity ward for expectant mothers giving birth under fire.

Caesarean sections are performed routinely in a purpose-built operating theatre, not far from a children’s dialysis unit, the MRI and PET scan facilities, and a creche that can take in 450 children, mainly those of employees.

According to Dr Weissman, there are European hospitals, which he declined to name, hoping to replicate a similar model for their own cities.

That this has all been accomplished in what is still, ostensibly, a car park is a feat not lost on the patients relying on it.

“I never imagined this is how I would give birth to my first daughter – in a car park,” said Sapir Shlomo, cradling her baby Shaya within a narrow, modest lodging in the maternity ward. “But this is Israel, and it’s how we live, and it’s what we love. We’re Zionists, and one day it will be a great story to tell my little girl.”

Grazia Elias, holding her twin newborns Shadi and Sharbel, said she was alarmed, at first, about having a baby while the country was under attack.

“It was really hard for me in the beginning,” she said. “But the doctors here were great. They gave me so much help; more than expected. Better to be here in the carpark where I know nothing can happen to me than anywhere else right now.”

In the event of missile fire, hospital directors gather in a situation room where they can monitor live images of CCTV cameras streaming outside the facility, a dashboard telling giving them vital numbers of staff in the building, staff stuck abroad, patients on hand, and levels of blood supplies and oxygen currently available.

“Most hospitals don’t have facilities like this,” said Dr Weissman. “We’re lucky or unlucky, depending on how you look at it.”

But working in a carpark isn’t without its challenges, said senior nurse Amariya Abu-Khamir Jahan, who runs an outpatient clinic for haematology patients, most of whom are immunosuppressed.

Treating them in a carpark, she said, was hardly ideal.

“It’s weird,” she said of the circumstances. “It’s not simple, they are very complex patients.”