This map shows estimated land values (without buildings) in Seattle by using an inverse distance weighting interpolation. As you might expect, downtown real estate is pretty valuable, while land is worth less farther North and South. Note: this is just to get a general idea of land value, if you want to know the value of your land, you would want to use the King County Parcel Viewer tool.

Also I made the legend draggable to make it easier to match up values!

Data:
King County GIS Portal