The towering 60-kilometer-long (37-mile-long) Pío XI Glacier, also called Brüggen, is the granddaddy of all Patagonian glacial ice fields. Located in Bernardo O’Higgins National Park, the glacier takes a 90-degree turn on its way down to the sea and is almost twice as large as Singapore. Glaciologists are not entirely clear on why Pío XI is the rare glacier—along with Argentina’s nearby Perito Moreno at the base of the Torres del Paine cordillera—that is growing rather than receding.