Chikuya Shrine is a very ancient shrine near Iya in HigashiIzumo near the shore of the Nakaumi Lagoon. It is listed in the Izumo Fudoki which means it was in existence before the eighth Century. It is also listed in the 10th Century Engi Shiki which means it received offerings from the central government. It was moved to its current location in 1666 following a massive flood at its previous location about 1K south.
The primary kami of the shrine is Kotoshironushi, the son of Okuninushi who suggested that Okuninushi cede the land to the Yamato envoys. His main shrine is Miho Shrine not far from here on the Mihonoseki Peninsula. Nowadays he is equated with Ebisu.
The secondary kami enshrined here is named Hayatsumujiwake, and I can find absolutely no reference to him except that the Izumo Fudoki lists a Hayatsumuji Shrine, so I suspect that stood here originally until the Chikuya Shrine was relocated here.
As well as a covered sumo ring there are numerous secondary shrines within the grounds including a Tenman Shrine enshrining Tenjin, an Ise-gu enshrining Amaterasu, an Akiba Shrine for protection against fire, a Munetada Shrine, a Meiji era shrine with connections to the Kurozumi-kyo sect, an Inari Shrine, a Kizuki Shrine, Kizuki being the old name for the area where Izumo Taisha is located, a Konpira Shrine, and a Sumiyoshi Shrine.