I wonder if they will still be washing up a hundred years from now?

A container filled with millions of Lego pieces fell into the sea off Cornwall in 1997. But instead of remaining at the bottom of the ocean, they are still washing up on Cornish beaches today - offering an insight into the mysterious world of oceans and tides.

"Let me see if I can find a cutlass," says Tracey Williams, poking around some large rocks on Perran Sands with a stick.

She doesn't manage that, but does spot a gleaming white, pristine daisy on the beach in Perranporth, Cornwall. The flower looks good for its age, seeing as it is 17 years old.

It is one of 353,264 plastic daisies dropped into the sea on 13 February 1997, when the container ship Tokio Express was hit by a wave described by its captain as a "once in a 100-year phenomenon", tilting the ship 60 degrees one way, then 40 degrees back.

As a result, 62 containers were lost overboard about 20 miles off Land's End - and one of them was filled with nearly 4.8m pieces of Lego, bound for New York.

No-one knows exactly what happened next, or even what was in the other 61 containers, but shortly after that some of those Lego pieces began washing up in both the north and south coasts of Cornwall. They're still coming in today.