A pile of twisted, rust-red metal lies beside the pot-holed road that marks the perimeter of Munda Airport, a legacy of the vicious fighting that took place in this part of the Solomon Islands more than 70 years ago. The debris - largely unrecognizable but including machinery parts and vehicle wheels - was collected from a patch of land that has been earmarked as the site of a new fire station for the expanding airport. An engineer and a team of local workers are surveying and preparing the plot before construction work gets under way.

They are accompanied, however, by a three-strong team of New Zealand-based experts whose task is a good deal more dangerous. Among all the harmless remnants of the fighting on this one island between Japan and the United States are countless unexploded artillery rounds, mortar shells and bombs dropped from aircraft, right down to individual bullets fired from rifles and pistols.

Corroded and unstable

Seven decades after they were fired, the munitions are corroded and unstable. And those found at Munda Airport - which was a key Japanese airfield during World War II - need to be removed and defused before work can begin.

"The runway was extended back in 2012 and we are now preparing the way for the building of the fire station and the installation of a security fence around the perimeter as well as navigation aids for aircraft and ground lighting," Russell Allison, associate director of the ground engineering and tunneling division of US-owned engineering company AECOM, told DW. 

"This part of the island was heavily bombarded during the war and old photos show it looking like the craters of the moon," he said. "We knew before we started that there was likely to be a reasonable amount of UXO [unexploded ordinance] and that is what we have found."

The haul to date, on this one small patch of the island, includes a number of 155 mm artillery rounds that would have been fired from US howitzers located on the outer atolls of the island before ground troops were unleashed on the defenders.

The UXO team is placing short poles topped by orange flags at spots where metal has been detected that requires further examination. If the debris is harmless, a heavy digger is called in to remove it. If it is another shell, the police are summoned and it is carefully removed to a safe storage site until it can be dealt with.

Operation Render Safe

Every two years, specialist officers from the Royal New Zealand Navy visit the Solomon Islands to gather unexploded ordinance from different locations and dispose of it. In September 2016, a team aboard HNNZS Mamawanui spent three weeks locating and destroying UXO in an exercise known as Operation Render Safe 2016. In the final five days of the project, conducted in the Russell Islands, to the south of Munda, they recovered more than 181 kilograms of ordnance.

The work is important and undoubtedly saves lives, but a visit to Alphy Paulsen's museum - where the exhibits are so numerous that they are spreading outside the large shed in his garden - will indicate just how much military hardware lies in the surrounding jungles and the encircling lagoon.

Over the course of 20 years of excavations - primarily between the US landing beaches and the town of Munda - Paulsen has discovered everything from aircraft propellers to water canteens from both sides, medicine jars, Coca-Cola bottles, belt buckles, buttons, shavers, helmets and the skeletal remains of pistols, rifles and machine guns.

Inevitably, he also comes across human remains in collapsed foxholes and indentations left by exploding shells. Many come from a feature known as Bloody Hill, where the Japanese held up the US forces for three days in July 1943. Each time, he marks the spot and returns with representatives of the US or Japanese embassies in Honiara, the capital, so the remains can be repatriated.

But a lot of his discoveries still have the capacity to maim or even kill. Thousands of rounds of ammunition sit in piles on his tables, from stubby pistol bullets to the longer bullets fired from the rifles of both sides and 20-centimeter-long rounds from recoilless rifles. A wooden box contains a Thompson sub-machine gun from which the wooden stock has rotted away and around 20 hand grenades - all of which have been made safe, he reassures.

Unexploded rounds

Outside, alongside unexploded mortar and artillery rounds, stands a 250-pound (113 kilogram) bomb that was dropped on the Japanese airfield at Munda - the site of the modern-day airport. "It was just a couple of centimeters below the surface and they found it when they were doing the expansion work there a couple of years ago," Paulsen told DW. "It was just off to one side of the runway, meaning that for years aircraft were landing just a couple of feet away from this thing.

"The forest around here is full of these things," he said, indicating his haul with a sweep of his arm. "And I guess we will never find them all."

There are frequent reminders of the threats that UXO still pose to local people; islanders that I speak with tell of friends or relatives killed or maimed by left-over weapons. One lost a cousin who was clearing land for a homestead and unwittingly lit a fire above a bomb that exploded due to the heat. Others tell of fishermen who have lost limbs trying to open bombs to extract the explosives to go reef fishing.

The US is also active in measures to locate and destroy weapons, Keithie Saunders, the consular agent of the US in Honiara, told DW.

"We are funding programs to teach police how to safely detonate these weapons when they are found," she said. "This August marks the 75th anniversary of the Battle of Guadalcanal, one of the bloodiest and most important of the entire campaign in the Pacific, but there is still a lot of work to be done to make sure the people who live here now are safe."