The kairō and the rōmon were among the most important among the garan elements which appeared during the Heian period. The first surrounded the holiest part of the garan, while the second was its main exit. Neither was originally characteristic of Shinto shrines, but in time they often came to replace the traditional shrine surrounding fence called tamagaki. The earliest example of a kairō/rōmon complex can be found at Iwashimizu Hachiman-gū, a shrine now but a former shrine-temple (神宮寺). The rōmon is believed to have been built in 886, and the kairō roughly at the same time. Itsukushima Jinja is an example of the mature form of the complex.