'Correspondence', works like a modern archaeological investigation.
Hajime travelled in the area of Torres Vedras, north of Lisbon. There lie the most famous archaeological and historical ranges for the fortifications of the Napoleonic war in 1810. Tracing one of these old ranges, Kimura documented the current landscapes and trash that he found on his walks, while writing down the coordinates, dates and times, like an archaeologist.
"This is a meta-message I sent at a place famous for archaeology, to future archaeologists, or to anyone who happens to find a relic from the past. What we now recognised as mere trash may become a clue to explore the past in a few decades or even a few hundred years. I decided to transmit this message to the people of the future who have yet to see it, photographs of trash and the surrounding landscape where the trash had fallen. I combined them in this book, and let you do the "digging". That is the basis of this story."- Hajime Kimura