Disputed area: 60–72 km²
The 8.5 × 8.5 km bounding-box figure (~72 km²) includes inaccessible decorative terrain. A community survey of the invisible playable boundaries lands closer to ~60 km² of strictly playable area. This entry covers the Velen+Novigrad continuous landmass only — Skellige (~64 km²) and the DLC region of Toussaint are not represented.
72 km² — TechTimes derives ~72 km² for the contiguous Velen+Novigrad landmass (article labels it 'Novigrad'), from an ~8.5 × 8.5 km bounding box. Skellige (~64 km²) and Toussaint (DLC) are separate and excluded here. 60 km² — Reddit user mapped the invisible playable boundaries inside the same outline, arriving at ~60 km² of strictly playable area (excluding inaccessible mountains and decorative out-of-bounds terrain).