The battery returned fire on the German Navy in 1914
The restoration of 19th Century gun battery, costing more than £1m, has been completed in Hartlepool.
A trust began refurbishing the Heugh Gun Battery, on the town's Headland, in 2000 after the derelict site became a magnet for anti-social behaviour.
The site now boasts 17 artillery pieces, an interactive visitors centre, workshop and cafe.
Built in 1859, the battery is famous for returning fire when the German Navy bombarded the town in 1914.
John Southcott, chairman of the Heugh Gun Battery Trust, said: "The battery was in a state of absolute dereliction and it was appalling.
"We had everything from burnt out cars, needles, broken glass and graffiti.
"It is now a safe area and it will be preserved for the country."
He said the battery's original guns, which were scrapped before the restoration project, had been replaced with artillery pieces of historical significance, including an anti-aircraft gun used by the British during the Axis siege of Malta in World War II.
The battery missed out on £2m when it failed to reach the final of the BBC's Restoration programme in 2006.