Designed by Richard Rogers and completed in 1986, the building is one of the most celebrated of its kind in London and famously though the building is modern it contains older gems such as the 18th century Adam Room, which date from much earlier.
If you're serious about getting inside, however, you will have to get in the queue pretty early. Though 6,464 people got to visit during the 2010 Open House event, it is known for long queues, and those who want to get round a few places could probably use their time better heading for shorter queues.
One other nearby gem with shorter anticipated queues is 19 Princelet Street, which is open again this weekend, and where your author will be volunteering. However, for more on Lloyd's, visit http://www.londonopenhouse.org/public/london/find/detail.asp?loh_id=3729