Possible Clues:

• Like the construction of a honeycomb?
• Vault across bull without protection of mobile phone
• Like mobile phone that's broken caller left around middle of pub?
• Built like a prison, but with holes in the fabric
• After a lull, echo rings round in compartments
• Like some building blocks
• Porous
• Having a porous texture
• Holds the monk and college artist back describing small rooms
• Consisting of small compartments