VERDICT: MISLEADING The viral claim "Scientists Discovered Huge Octopus City underwater" is an exaggerated distortion of a real but modest scientific finding. Scientists did discover an unusual aggregation of octopuses, but it is NOT a "huge city" — and the very researchers who made the discovery explicitly stated that describing it as a "city" is inaccurate. **What actually happened:** In Jervis Bay, Australia, researchers found a second site where gloomy octopuses (Octopus tetricus) live at unusually high density — up to 15 individuals — in dens excavated in a bed of discarded scallop shells (a "midden"). The researchers nicknamed the sites "Octopolis" and "Octlantis," but these nicknames were never used in their scientific papers. **Two claim-linked findings from primary sources:** 1. **The "city" description is explicitly rejected by the authors.** In their peer-reviewed addendum, the researchers wrote: "Popular media reports have described this site as an 'city' designed by octopuses, but that is not an accurate description of the site." They also noted: "In a series of news reports written about our paper, a tendency has grown to exaggerate what we reported. The site was described as 'an underwater city' of octopuses (Science, The Guardian)... We want to take the opportunity not only to correct some misconceptions about our findings." (Source: PMC/Commun Integr Biol, Scheel et al. 2017) 2. **The scale is tiny, not "huge."** The original peer-reviewed paper reports the site was "occupied by 10-15 octopuses on eight different days" — a dozen or so animals in a shell bed, not a "huge city." The aggregation appears to be an inadvertent byproduct of food availability and predation risk, not intentional "city-building" by octopuses. **Primary sources used (both peer-reviewed journal articles):** - https://pmc.ncbi.nlm.nih.gov/articles/PMC5824970/ — Scheel, Godfrey-Smith, Linquist, Chancellor, Hing & Lawrence, "Octopus engineering, intentional and inadvertent," *Communicative & Integrative Biology* 11(1):e1395994 (2017). This is the authors' own correction of the media exaggeration. - https://www.tandfonline.com/doi/full/10.1080/10236244.2017.1369851 — Scheel et al., "A second site occupied by Octopus tetricus at high densities, with notes on their ecology and behavior," *Marine and Freshwater Behaviour and Physiology* 50(4):285-291 (2017). This is the original discovery paper. **Bottom line:** A genuine scientific discovery exists (unusually dense octopus aggregation), but the "huge octopus city" framing is a media exaggeration that the discoverers themselves publicly corrected. The claim is therefore misleading.