LAS VEGAS (KLAS) — Construction workers have started pouring 600,000 square feet of concrete for flooring in the new expansion of the Las Vegas Convention and Visitors Authority.

To give you an idea of how much space that covers — it could hold 333 volleyball courts. The exhibit hall will have the largest column-free space in North America.

This extensive part of the project will take as long as five months to complete and is a major step in the expansion project, which is 77% complete, according to the LVCVA.

The $980 million West Hall expansion will add 1.4 million square feet of space to the existing 3.2 million square foot campus. The expansion will feature an outdoor plaza and a grand atrium. It’s expected to be finished in December 2020.