For years, a constant wave of tourists has been destroying some of the most popular natural spaces in the world.

Most tourist hot spots have started to put up signs instructing visitors on best practices, but the Khao Yai National Park near Bangkok in Thailand has decided to get a bit more creative. The park recently announced that they will be making an effort to keep track of tourists who litter, and then send their trash back to their homes in the mail as a blunt reminder of their transgression. Anyone who visits the park will be required to register with their address, which will make it relatively easy to track them down if they make a mess.

Thailand’s environment minister Varawut Silpa-archa also said that offenders will be reported to the police. Littering in a state park can result in very serious fines and even up to five years in prison.

The effort has reportedly already begun. Varawut Silpa-archa posted photos of litter that was collected from the park and packaged for shipping

“Your trash – we’ll send it back to you,” a post on Facebook warned.

The photo showed a collection of empty plastic bottles, cans, and snack wrappings placed in a box. There was also a note on the box that read, “You forgot these things at Khao Yai National Park.”

Park officials have warned that litter is not only unsightly, but it can also be dangerous to local wildlife.

Any time you are exploring in nature it is best to have a “leave no trace” attitude and take everything home with you, including your trash. This also includes not making any changes to the terrain. Even simple rock formations that have become popular on Instagram have been known to disrupt wildlife habitats.

Khao Yai National Park is the oldest national park in Thailand and stretches for more than 770 sq miles.