Awataguchi was an entrance to Osaka no seki (Osaka Barrier, which was one of the barriers of the road system of old Japan) and regarded as a major starting point of the road from Heian-kyo to Togoku (the eastern part of Japan, the term is used in the old days) via Omi Province.
また、粟田口は逢坂関への入口であり、平安京から近江国を経て東国に至る道の起点として重要視された。