The Dome and Main Hall Interior

The dome spans 65 metres. Its reinforced-concrete ribs radiate towards the centre, and the structure is crowned by a lantern, a glazed feature admitting light from above. The circular central auditorium forms the heart of a building whose plan resembles a symmetrical four-leaf clover.

When built, it was the largest reinforced-concrete dome in the world. That record concerned a particular structural material, not every type of roof. Berg used concrete reinforced with steel and limited ornament, exposing the structure rather than concealing it behind decorative cladding.

From the outset, the building was designed for gatherings, exhibitions, performances and sport. The contractor handed over the structural shell in December 1912. The ceremonial opening followed on 20 May 1913, alongside the inauguration of the Centennial Exhibition.

In the 2023 film The Hunger Games: The Ballad of Songbirds and Snakes, the interior became the arena for the Tenth Hunger Games. Its on-screen destruction belongs to the fictional story, not the history of the monument. Visitors can compare the actual geometry of the dome with its role in the story of young Coriolanus Snow and Lucy Gray Baird.