After the excavation, the concrete shell of the passageway can be built.

The dilapidated concrete shell was eventually torn down in 1952.

The concrete shells of the old facilities are visible in a park area.

The house was a concrete shell, bare of its furniture, windows and doors.

The buildings were looted of everything but their concrete shells after the invasion last year.

Still, the concrete shell may reveal something, and this is the first possible physical evidence we've had to deal with.

"We could have been left with a concrete rusting shell."

Eventually, it was nothing more than an empty, roofless, concrete shell.

Its roof was the largest concrete shell in the world at that time.

What lay inside the concrete shell, therefore, was still a complete mystery.