Lockholes
From Tolkien Gateway
When the Shire was taken over by Sharkey's Men during the War of the Ring, the storage tunnels of Michel Delving were converted into the so-called Lockholes. These were prison cells for those who rebelled against the new regime, among whose inhabitants were Mayor Will Whitfoot, Lobelia Sackville-Baggins, and Fredegar "Fatty" Bolger.
