A four-hour bus journey west of Mendoza will leave you at the stone-entrance of the Aconcagua National Park. After a four-hour trekking through small paths up the mountain along Rio Horcones, you will eventually reach the Confluencia base. The first thing to do is to check-in — so they know at the entrance that you had made it — and then visit the doctor for a quick health check.
The Park Ranger’s shelter stays standing through the whole year, and is built from T-Plak, a long lasting, weatherproof material made from recycled Tetra Pak cartons. It has a corrugated iron roof with solar panels resting on it. The site has around five companies that offer different services like guided trekking tours, fantastic meals, renting of equipment, tents or a bunk bed in one of the geodesic domes. I stayed and fully recommend Inka, which are linked to ethical mountaineering NGOs Leave No Trace and UIAA. The domes can take different shapes and are brought up every year. They are built on site and wrapped in plastic sheeting, which is not the most sustainable material to produce, but its extremely durable, weather-proof and designed for reuse.