was the twentieth of the sixty-nine stations of the Nakasendà Â. It is located in the present-day town of Karuizawa, in the Kitasaku District of Nagano Prefecture, Japan.
This post town was named Oiwake, which means "where two roads split," because it was at this point that the Nakasendà  split from the Hokkoku Kaidà Â. In the late 17th century, during the Genroku period, it flourished as a post town that could hold over 200 guests. There are still many remnants from the Edo period in the town today.
Though not a neighboring post town, Matsuida-shuku also provides a direct connection to Oiwake-shuku along the Nakasendà Â, by way of a minor hime kaidà Â. This hime kaidà  allows travelers to avoid the Usuinoseki Checkpoint, one of the major checkpoints along the highway.