For the past 25 years, the Alfred Wegener Institute has operated a long-term observatory in the Arctic deep sea: the HAUSGARTEN. Located between Greenland and Svalbard, it is where researchers investigate natural and climate-change-related changes in a polar, marine ecosystem – from the ocean’s surface to the seafloor, 5,500 metres below. Many of the observatory’s stations are located below the sea ice, while its autonomous systems take measurements year-round, i.e., even when left unmanned.