A wind turbine tower includes a plurality of tower sections axially aligned and connected together. Each tower section includes an inner wall having a tapered cylindrical shape concentrically positioned within an outer wall having a tapered cylindrical shape. An annular space is defined between the inner wall and the outer wall, and a layer of concrete is disposed within the annular space. A plurality of post-tensioning cables extend longitudinally within the annular space or outside the outer wall, such that a first one of the tower sections is connected to a second one of the tower sections by a plurality of the post-tensioning cables.