The Montblanc 1858 product line is inspired by the legendary Minerva professional watches of the 1920s and 1930s, designed for military use and exploration. The Montblanc 1858 line reinterprets these historic timepieces, evokes the spirit of exploratory mountaineering and embodies the current trend of a return to nature. The Montblanc 1858 Geosphere Ultra-Black is dedicated to the mountaineering challenge of the seven summits of the world, the holy grail of adventure mountaineering. It is presented in a 42 mm aged steel case with contrasting black and white design details. This model features a world time complication developed by the watchmakers of the Montblanc Manufacture in Villeret, with two domed globes that rotate in opposite directions and complete a rotation in 24 hours. The two globes are surrounded by a scale with the 24 time zones, together with a day/night indication in contrasting colors. It thus offers an instinctive way to appreciate the different time zones, with the help of the luminescent continents, which improve visibility and performance in the dark. The watch is completed with a black calfskin strap with beige stitching.