The shortest path tour problem (SPTP) consists of finding a shortest path from a given origin node s to a given destination node d in a directed graph with nonnegative arc lengths with the constraint that the optimal path P should successively and sequentially pass through at least one node from given disjoint node subsets. In this talk, it will proved that the SPTP belongs to the complexity class P and several alternative techniques will be presented to solve it. Furthermore, some variants of the SPTP will be discussed and proved to be special facility location problems.