Sake Barrels 酒樽
These are sake barrels (酒樽). Though empty physically speaking, they're not so, in the spiritual sense. These're called decoration barrels (飾樽).
In ancient Japan, rice wine was known as miki (神酒), which means, "god wine". According to Shinto, sake has the power to unify man with the gods. During religious ceremonies, worshipers are given wine. Most shrines get donations from sake brewers but two shrines regulate the donations, namely, Meiji Jingu in Tokyo and Ise Jingu in Mie prefecture.
Surprisingly, sakeis normally not kept in wooden barrels for too long as the taste and smell of wood in the sake will then get too strong. Instead, they're kept in steel tanks.
(Summarized from: search.japantimes.co.jp/cgi-bin/ek20071016wh.html))
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