The true extent of the road network is not completely known, since the Spaniards, post conquest, dug up the road completely in some areas, or allowed it to deteriorate and fall into ruin under iron-clad horses' hooves, or the metal wheels of ox-carts.[1] Only about 25 percent of this network is still visible. Different organizations such as UNESCO and IUCN have been working to protect the network in collaboration with the governments and communities of the six countries through which the Great Inca Road passes.