People using the Sanin-do Road from Heian-kyo, passed through Oeno-seki (the Oe gate station) placed on Oeno-saka Slope, located in the boundary between Yamashiro Province and Tanba Province, in order to bid farewell to the capital; therefore, it was known as a place of utamakura (a place name often used in ancient Japanese poems) (even before the capital was moved to Heian-kyo, this route was used for going to Heijo-kyo via Yodo-gawa River).
平安京から山陰道を下る場合、山城国と丹波国の国境にある大江坂に設けられた大江関（おおえのせき）を必ず越えて京と別れを告げることになった事から、古くから歌枕の地として知られていた（平安遷都以前にも淀川経由で平城京に向かう場合の経路とされている）。