When Powered by RedstoneEdit
When you power a Land Mark with a Redstone Torch, the Land Mark will display blue lines in every direction for a distance of 64 blocks, which is also the maximum size of a Quarry.
When Right ClickedEdit
If you right click a Land Mark, it will show a red line going towards all other Land Marks it can connect to in order to form a rectangle. This action will also make two line segements on the adjacent sides of the rectangle to form a rectangle out of the lines formed, if there are Land Marks all corners.You must do this before adding a Quarry to the Land Marks.
The primary purpose of a Land Mark is to label the dimensions of a Quarry.
To do this, you will need 4 Land Marks. Place the Land Marks in 4 directions that form a square. When you right click the Land Mark, it should be possible to place a Quarry, which will have the dimensions that were specified by the Land Marks.
For Use as DecorationEdit
The Land Mark can also be used as a decorative item.