The building’s most memorable feature, however, is undoubtedly the great dome, which rises 200 feet above ground and is visible for miles. The dome houses the chiming clock and Little John, a ten and a half ton striking bell, which is reputed to have the deepest tone in the country. Like its colleague, Big Benn, in London, the fine balance of the clock is achieved by using coins of the realm. One commentator, writing in a magazine article published to mark the 50th anniversary of the Council House, said of it: "Imagine for a moment the scheme without the dome".

The view from the Market Place would no doubt have appeared acceptable as a normal and satisfying piece of architecture in a large market town, but it could be that the dome had itself lifted the city into a different category, making an indelible impression on visitors seeing the city for the first time, and also having a subconscious effect on the inhabitants.

The four groups of figures at the base of the dome symbolise Commerce, Civil Law, Prosperity and Knowledge. One of them was sculpted by James Woodford, who was later commissioned for the Robin Hood statue which stands beneath the walls of Nottingham Castle.