Exploring Vladivostok’s abandoned maritime fortress

Underneath the hills of the Russian city of Vladivostok are the remnants of what used to be one of the world's most powerful maritime fortresses.

It was built at the end of the 19th and the beginning of the 20th Century when Vladivostok was home to the imperial Russian fleet which made the city a potential target.

Many parts of the fort were also used during the Soviet Union.

Abandoned for decades, some parts of the fortress are now open to tourists.

The BBC Travel Show's Carmen Roberts reports.

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