Buddhist sermon hall
A hall within a Buddhist temple complex used for delivering sermons or lectures on the Dharma.
The sermon hall of this temple was built in the Edo period.
法堂 is a more general term for a Dharma hall or lecture hall in a Buddhist temple, while 転法輪堂 specifically emphasizes the act of turning the wheel of the Dharma (preaching).
From 転法輪 (turning the wheel of the Dharma, i.e., preaching) + 堂 (hall). The exact historical derivation is uncertain, but the term is a standard Buddhist architectural designation.