For the past 122 years, Spreewald in Germany has been delivering local post by barge.
In this rural area, many houses cannot be accessed directly by road, making traditional delivery methods unfeasible.
Postwoman Andrea Bunar explains, "many homesteads can only be reached by boat. And with the post barge, it is a simple and fast way of delivery."
Bunar's delivery area spans approximately 8 km and contains 65 households. A full delivery takes around two hours.
Deutsche Post decided to implement the post barge in 1897 meaning that residents who grew up in the area have known this system of delivery their entire lives.
"In the winter months, everything ran over the ice. Sometimes the postman came with the ice skates when it was frozen" remembers barge ferryman Gunter Brandt.
Today, the post is delivered by boat no matter the weather.
"In windy weather, we are out there with rain, sleet, hail, everything is there. To keep the boat on track when there's a lot of wind, that is a special challenge" says Bunar.
"The barge is made from aluminium making the barge very light - both a blessing and a curse," she explains.
Bunar delivers approximately 600 letters and 70 packages every week. Each package weighs up to 31.5 kilograms. By delivering the post through by barge Deutsche Post saves around 350 kilograms of CO2 emissions per season