A litter-picker hopes a 35-year-old fizzy drink can and a packet of crisps from the 1980s will help educate children about the environment.
Tracy Menzies set up the Wickford Wombles group in Essex to keep their area tidy and fundraise to plant trees.
She now uses some of the finds to educate children.
"We tell the kids, 'this can is the same age as your parents but you can still read the writing. It's almost as pristine as the day it was dropped'."
Ms Menzies added: "It's fascinating to think some items will sit there in a hedge or woodland for 40 years, potentially trapping wildlife, when a lot of it could have been recycled in a week."
The Facebook group of "environmentally conscious tree-huggers" was set up two years ago, and members focus their efforts on areas of undergrowth where council workers find it hard to get to.
The 750-strong group of pickers have found all kinds of items, such as asthma inhalers, glasses, pregnancy tests, a rising number of face masks and gloves in recent months due to Covid-19, and even the odd £10 note.
A post about their New Year's Eve search read: "A bike, a shopping basket, a can abandoned in 1996, two sacks of general rubbish retrieved from the river and banks... only about a 20/30-metre stretch covered... and a cash reward! I love it when that happens! We earned it mind you."
Ms Menzies urged people to think about the type of packaging they buy and how they dispose of it.
She said: "The amount of rubbish we find is disappointing when the easy solution is for people to just put it in the bin, which is often right next to where the litter was dropped."