Constructed in the 1680s for Louis XIV, and measuring nearly four metres in diameter and weighing a couple of tons apiece, Vincenzo Coronelli’s great globes “are a simply amazing celestial and terrestrial pair,” writes Matthew Edney, who saw them at the Bibliothèque nationale de France in 2019. But, he goes on to say,

[T]he globes were effectively useless. Their imposing grandeur made them completely the wrong size to be used effectively. Smaller globes—made with diameters between 0.075–1.7m (3–67″)—could be easily turned to show specific parts of their convex surface. Or, people could enter within much larger globes, called georamas, turning themselves around as necessary to see all parts of the earth on the concave interior surface. Coronelli’s globes were far too large for the former, and far too small for the latter.

This unavoidable reality inverted the usual physical relationship between viewers and globes, undermining the viewer’s usual sense of intellectual domination and converting the globe-viewing experience to one of awe and amazement. As a result, no-one really knew quite what to do with them[.]

Their difficult size and limited utility is why they’ve spent most of their 340-year existence hidden from view, though they’ve been on display since 2005 at the BNF’s François-Mitterrand site (see the above BNF video, in French).