Largest underwater city in Minecraft

Largest underwater city in Minecraft
Who
Jeracraft
What
5,000,000 total number
Where
Not Applicable
When
29 July 2017

On 29 July 2017, YouTuber and Planet Minecraft master-builder Jeracraft celebrated his 300,000-subscriber milestone with a tour of his Lost City of Atlantis. Prior to this, Jeracraft spent two weeks setting up and piecing together "Over 5 Million blocks with the main fortress alone", initially intending to build some kind of ruin structure. However, Jeracraft felt compelled to go further, imagining how this fabled city would look with statues and towers.