Dutch colocation provider Interxion, plans to turn a long-abandoned World War II German submarine base in Marseille, into a data center.

The company has set out €140 million to convert the uncompleted Southern France “Martha Base” bunker which was built in 1943 to accommodate up to 20 U-boats; into a data center for corporate clients.

“It is not our job to restore historical buildings, usually we build from scratch. But this was an opportunity and Marseille is a major telecoms, cloud and digital hub between Europe, Africa, the Middle-East and Asia,” Fabrice Coquio, Interxion France director.

The bunker was meant to be the main German U-boat base in the Mediterranean during the German occupation of France, but Allied forces bombed the city in May 1944 and took it back in August that year.

After the war, the facility was used for storage by the army and customs service, but it had been abandoned in recent years.

For Interxion, this abandoned facility is strategically located in today’s network path. Coquio added that the port city where the bunker is sited, is France’s second data hub after Paris and the tenth-biggest in the world with about a dozen submarine and terrestrial data cables arriving there, and getting Martha Base will bring Interxion as close as possible to those cables.

Upon completion, the data center will span 25,000 square meters and requires 24MW of power supply. Back-up generators will also be installed to avoid outage.

The first phase of the restoration is set to be completed by March.

Headquartered in the Netherlands, Interxion is a European provider of carrier and cloud-neutral colocation data center services with over 1600 customers across 50 data centers.