The Valley of the Indus River: The believed origin of the swastika symbol because it has been the source of the earliest presence of the symbol. From the Indus River, the symbols migration extends west towards Persia and Asia Minor to Hissarlik and Balchistan(15).
The above picture is of seals found in the Indus River valley. Attention to top right seals.
(15) Heller and Roth, pg. 29
at 4:02 PM