A four and three-quarters tatami mat size teahouse with a cornerboard named after a poem by Sotoba and particularly favored by Oribe FURUTA that is also known as Horadoko (lit. cave alcove) due to the wing wall extending into the alcove - giving it the appearance of a cave.
蘇東坡（そとうば）の詩から名付けられた古田重然（ふるたおりべ）好みの四畳台目に隅板を加えた茶室で、床の間は袖壁が出ているために洞の様に見える事から洞床（ほらどこ）と呼ばれている。