A voluntary group has collected nearly 450 bags of rubbish since it was formed in September last year.
Blackwood Action on Litter Community Group, which was set up by Pontllanfraith residents Donna Szarun and Sali Daniels, meets every month for regular litter picks.
The group has so far collected stray trolleys, scooters, tyres and sofas, as well as a 22-year-old Doritos bag.
But perhaps most alarmingly, the group has “picked up a lot of Calvin Klein underpants”, according to Mrs Szarun.
Mrs Szarun said: “Sali and I both started picking up litter when out walking our dogs.
“I bumped into Sali on Bryn Fields with a litter picker and we decided to start the group.
“We did our first pick in September and we’ve been out 12 times since.
“We’re an independent group and we organise our walks on the last Sunday of each month.
“We now have a regular group of more than 20 volunteers who turn up regularly. People turn up in rain or shine to help out.”
Mrs Szarun added: “We look forward to it. You can easily make a difference and anyone can do it.
“We’ve had so much support – people beep at us when passing in their cars and we’ve got a lot of support on social media.”
The group has carried out litter picking sessions in and around the Blackwood area, including Brewers Lodge and the Sirhowy Valley Country Park, as well as main roads and cycle routes.
Mrs Szarun said: “Sali and I didn’t envisage doing so many picks. People are engaging on social media and offering a lot of encouragement.
“We’ve even been on picks with pupils from Penllwyn Primary School and Bryn Primary School.
“People are now starting to bring their own litter pickers with them too.”
Mrs Szarun added: “We’d like to engage the community more and raise awareness. We’d like to link up with more groups too.
“We couldn’t have done this without Andrew King from Keep Wales Tidy. We wouldn’t have been as organised without his help.”
Andrew King, Caerphilly project officer for Keep Wales Tidy, said: “Keep Wales Tidy are proud to support Blackwood Action on Litter Community Group. It’s great to see them go from strength to strength in their first year as a group and I want to congratulate all the volunteers for their hard work.”