More than 100 examples of graffiti etched on to trees in the New Forest have been logged for posterity.
Dates, drawings, poems and royal marks can be found on trees throughout the forest, some dating back centuries, but have never been formally recorded.
The New Forest National Park Authority (NPA) said while urban graffiti is seen as a blight, "ancient scribblings are a window into the past".
Visitors are being encouraged to record any sightings before they disappear.
Over time, the tree graffiti (also known as an arborglyph) warp, fade or get damaged by animals or people. Trees falling over or dying also pose a threat to the historical markings.
One of the most common etchings in the New Forest is a broad arrow head known as "the King's Mark" used to identify trees reserved for building Royal Navy ships, the NPA said.
When iron and steel became the preferred material for shipbuilding the trees remained untouched, and still bear their royal mark centuries later.
Concentric circles, or "witch's marks", thought to have been intended to ward off evil spirits, can also be found carved into bark.
There are also drawings of eagles, boats, houses as well as names, dates and initials.
The finds will form a record of "lost and forgotten stories" of the New Forest which will be made available online, the NPA said.