What is the biggest known structure in the universe ?

The Hercules-Corona Borealis Great Wall is the universe's largest known structure. It's a large galaxy supercluster about 10 billion light-years away from us. This structure spans around 10 billion light-years and contains tens of thousands of galaxies. In terms of scale, the Milky Way galaxy is just around 100,000 light-years across. A team of astronomers led by Jon Hakkila of the College of Charleston in South Carolina found the Hercules-Corona Borealis Great Wall in 2013. Its finding has aided scientists in better understanding the universe's large-scale structure and the distribution of galaxies within it.