Looking West along Hadrian's Wall in Northumberland with some rain approaching in the distance. Hadrian's Wall is about 73 miles long and crosses England from coast to coast. It was built by the Romans.
They had to make this to keep the Scottish people out of England at the time (that is basically true but it was more complicated than that) I don't think you needed a wall in Portugal but it would be a lot of fun searching your country. I love historic sites