Lago Greve sits in the northernmost corner of Chile's Magallanes province, tucked behind the Pío XI Glacier — the largest glacier in Chile — which effectively shields the lake from the outside world and makes it one of the most rarely visited bodies of water in Patagonia. Despite its obscurity, it ranks as the sixth largest lake in Chile, with a surface area roughly twice that of Paris. Its position within the Southern Patagonian Ice Field means that glaciers, including the Greve Glacier itself, feed directly into the lake.

Access is extraordinarily difficult. The lake's position behind the Pío XI Glacier means there is no straightforward overland or road approach, and reaching it requires a serious expedition-level commitment. The few paddlers who have made it to the lake have described kayaking across the face of the Greve Glacier and exploring the surrounding forest edges, with Volcán Lautaro — the highest peak of the Southern Patagonian Ice Field — dominating the skyline above.

The isolation of the lake has a direct effect on its wildlife. Animals encountered here have had little or no exposure to humans, resulting in unusually close encounters. Huemul deer, a rare and endangered Andean deer, have been observed watching paddlers from the undergrowth and approaching without apparent fear. The surrounding terrain also offers the possibility of retracing routes once used by the Kawésqar, the indigenous canoe people who historically traveled these waterways.

The paddling character of Lago Greve is defined entirely by its remoteness and scale. Those who have paddled it have noted the experience of being dwarfed by the surrounding landscape, with the reasonable likelihood of being among the first people ever to paddle its waters. The environment is raw and unmanaged, with no facilities, amenities, or established infrastructure of any kind for paddlers. Any expedition here requires full self-sufficiency and careful logistical planning. The combination of glacial terrain, unpredictable Patagonian weather, and the absence of rescue infrastructure makes this a destination suited only to highly experienced expedition paddlers with appropriate equipment and preparation.