A nano-colonnade structure-and methods of fabrication and interconnection thereof utilize a nanowire column grown nearly vertically from a (111) horizontal surface of a semiconductor layer to another horizontal surface of another layer to connect the layers. The nano-colonnade structure includes a first layer having the (111) horizontal surface; a second layer having the other horizontal surface; an insulator support between the first layer and the second layer that separates the first layer from the second layer. A portion of the second layer overhangs the insulator support, such that the horizontal surface of the overhanging portion is spaced from and faces the (111) horizontal surface of the first layer. The structure further includes a nanowire column extending nearly vertically from the (111) horizontal surface to the facing horizontal surface, such that the nanowire column connects the first layer to the second layer.