Haero's Wall

Ancient wall in the north of what is now Sigsland. The wall is (at least) thousands of years old. While the route of the wall remains, the structure itself is now incomplete. There are some stretches where the wall is made of Elfstone, but for most of its length now, the wall is at most rough stone, and in places merely a raised bank.
The wall is roughly semi-circular. It begins on the Caltsee coast some way west of the town of Estwater, winds its way in a seemingly haphazard fashion south and then southeast to the River Iril and the River Lynnen and then east as far as its end at the River Ard. The land encircled by the wall and the River Ard is now the counties of Estwater and Flaxingen.
History has forgotten who "Haero" was, or why he or should have wanted a wall built here. The land that the wall passes through was once the Kingdom of Martell.