We went to Bolton Abbey in the UK on our last trip, and I took this photo of the outdoor displays they had to inform visitors of the history of the place, give them a map, and direct them to the points of interest.
The signs were adhesive vinyl adhered to DiBond. That’s a good choice for things that need to last for a long time, we get 3-5 years from them. Although, we can also get similar life by direct printing onto the DiBond and applying a UV clearcoat. That lowers the cost substantially.