US sonar equipment at Giant’s Causeway among bizarre items found washed up on beaches

There was also a Canadian research buoy washed up at White Park Bay, still recording temperatures and sending data via satellite.

The charity has unveiled the 20 oddest objects found on its shores - which include the working Canadian research buoy, tiny plastic soldiers and thousands of neon pink detergent bottles - to shine a spotlight on marine pollution.

The problem continues to blight UK beaches despite growing public awareness of issues such as single-use plastics ending up in the seas, the charity said.

The National Trust is calling on staff, volunteers and the public to take part in beach or river cleans as part of a campaign to encourage people to tackle pollution and help the environment.

While some of the finds are of recent items and debris, some illustrate just how long waste can last in the seas.

They include 19th, 20th and 21st century shoes beached at Orford Ness in Suffolk, recent finds of a 1976 Claws crisp packet and a 1980s picnic at Formby in Merseyside, Smarties lids from before 1988, and even a post-Prohibition era bottle of rum from the US.

Some of the items that turn up on UK beaches are from far afield, including the can of fly spray from Russia, an aerosol can from Saudi Arabia, and plastic debris covered in goose barnacles thought to have drifted from the Caribbean.

But some of the debris is from closer to home, including a council bin from Peterborough, nicknamed “Pete”, which travelled 70 miles along the River Nene to Blakeney Point, and was later returned to its home constituency.

Cargo lost at sea can also account for rubbish washing up on beaches, such as nautical-themed Lego from a 1994 spill at Land’s End, and BMW parts, dog biscuits and oil-covered Mars bars from the MSC Napoli grounding off Devon in 2007.

The National Trust looks after 780 miles of coastline around England, Wales and Northern Ireland.

Phil Dyke, coastal specialist at the charity, said: “It’s fascinating to hear of the unusual things that land on our beaches, whether they’re relics from history or objects that have travelled thousands of miles.

“But as weird and wonderful as these items are, they tell a more serious story about the permanent nature of plastic, and the constant deluge of marine litter arriving on our shores.

“No-one in the UK lives more than 75 miles from the coast, so whether we’re in the city or the country, everything we do impacts on the health of our seas.”

He added: “The good news is that there has been a surge in public awareness in recent years, with more people joining beach cleans and swapping from single-use materials.

“Even small actions like using less packaging and picking up litter helpts to make a difference. We’ve all got a part to play in helping our seas recover.”