Nature preserve visitors shocked after common habit at iconic site creates damaging impact: 'We are urging people to stop the practice'

Visitors to Giant's Causeway, a UNESCO World Heritage Site in Northern Ireland, are damaging the landmark by putting coins between the stones.

Giant's Causeway is made up of basalt rock columns along the northern coast of Northern Ireland. Geologists date the formation to 60 million years ago. The site attracts visitors from around the world. Unfortunately, these visitors are reflected in the variety of coins that those who work at the landmark are finding wedged between the rocks.

According to the Irish Independent, the coins rust over time, and their expansion puts enough pressure on the rocks to make them crack or crumble.

Removing all the coins from the stones would cost over $40,000, Smithsonian Magazine reported.

Like many outdoor areas in the United States and around the world, visitors to Giant's Causeway should follow the "leave no trace" principles, ensuring that their enjoyment of the features does not have a negative impact.

"We know some may want to leave a token of their visit, but the coins are causing damage and we are urging people to stop the practice," said Cliff Henry, the National Trust nature engagement officer at Giant's Causeway.

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Unfortunately, many natural sites around the world are similarly damaged by tourists. Locals around Banff in Alberta, Canada, are dismayed by tourists littering. A bystander had to stop a tourist from climbing a tree in Deadvlei in Namibia.

Incidents like this can do more than damage the natural landscape. They can also endanger wildlife and humans. In Yellowstone National Park, for example, a man provoked a bison and was lucky to escape without serious injury. Earlier this year, a park ranger had to step in to save a child and their mother from a potential bison attack as the mother wanted to try to pet a bison.

While these incidents are dangerous and damaging, there are plenty of ways to have an eco-friendly vacation and treat these natural monuments with respect.

The easiest is to follow the National Park Service's seven "leave no trace" principles that can help anyone enjoy nature while preserving it.