About us
We’re a group of local and international guides with years of experience in the mountains of South America. Each of us brings a deep knowledge of the terrain, a strong commitment to safety, and a genuine passion for the outdoors. From high-altitude climbs to remote ski tours, we focus on good preparation, clear communication, and creating meaningful experiences in the mountains.
Our guides
Viktoria Georgieva
Viktoria is a certified ANGM mountain guide and ski guide (Asociación Nacional de Guías de Montaña, Chile). Co-founder of ARISTA and based in Valdivia, Chile since 2017, she works year-round in the mountains, leading tours and training aspiring guides. Having grown up in the mountains of Bulgaria, she has spent the past two decades exploring the Andes as both a scientist and a guide. Her experience ranges from climbing, skiing, high-altitude expeditions and scientific field trips, including trips to Aconcagua and the Patagonian Andes, as well as numerous ski descents on Chilean volcanoes. With a PhD in geology focused on the Andes and Patagonia, Viktoria integrates her geological expertise into her guiding work, offering clients unique insights into the landscapes and formations they encounter in the mountains. She also teaches geology and cartography to aspiring mountain guides, sharing her knowledge to help them better understand the natural environment they work in.
Carlos Fouilloux
Carlos Fouilloux is co-founder of ARISTA and an expert mountain guide with over 20 years of experience leading expeditions across the Andes. Specializing in high-altitude mountaineering, expedition logistics, safety in remote areas, he has summited numerous peaks above 5,000 and 6,000 meters, including Cerro Aconcagua, Ojos del Salado, Nevado Tres Cruces, Volcán San Francisco, Nevado Alpamayo, among others. Carlos is certified by the Escuela Provincial de Guías de Alta Montaña y Trekking in Mendoza, Argentina (EPGAMT) and the Asociación Nacional de Guías de Montaña (ANGM) in Chile. He has guided expeditions in Chile, Argentina, Peru, and Bolivia, and participated in numerous scientific expeditions in the Central Andes and the Patagonian Icefields focused on monitoring glacial dynamics.
Nils Fontenla
Nils Fontenla is an experienced mountain guide with over 20 years of leading expeditions across South America, including 35 summits of Cerro Aconcagua. Specializing in high-altitude mountaineering and rescue operations, Nils is certified by the Escuela Provincial de Guías de Alta Montaña y Trekking in Mendoza, Argentina (EPGAMT), with advanced training in mountain rescue, avalanche forecasting, and high-altitude medical response. He has led climbs on major peaks such as Cerro Mercedario, Cerro Tupungato, Nevado Huayna Potosí, and Nevado Huascarán. In addition to guiding, Nils trains rescue professionals and coaches high-performance teams. He is an active member of the Asociación Argentina de Guías de Montaña (AAGM) and the UIMLA.
Pedro Pablo Sermini
Pedro Pablo — or PePa, as his friends call him — has spent over two decades dedicated to the mountains. A passionate lover of nature and outdoor sports, he is a IFMGA-certified high mountain guide and also certified by ENAM/FEACH, as well as a physical therapist and former university professor. For more than 12 years, he has been training mountaineers and aspiring guides, combining technical expertise with a deep commitment to education. In his free time, you’ll find him with his family, climbing, or skiing in some beautiful corner of the world.
Nicolás García-Huidobro
Based in Villa Cerro Castillo, Nicolás is our lead guide for Patagonia, specializing in ski mountaineering, climbing expeditions, and high mountain ascents throughout the region. He also has broad experience leading expeditions across the Andes, including Chile, Argentina, Bolivia, Peru, and Ecuador. He has guided on well-known peaks such as Aconcagua, Huascarán, Alpamayo, and Chimborazo, and has participated in both summer and winter ascents, ski tours, and technical climbs. He is currently in the process of obtaining his IFMGA certification through ANGM in Chile. With a background in mountain rescue, Nicolás maintains a strong focus on safety, preparation, and continuous training in climbing and ski mountaineering.
María Paz Quercia Raty
María Paz is a certified mountain guide through the Asociación Nacional de Guías de Montaña (ANGM), Chile, and is currently completing her ski guide certification with the same association. With over 15 years immersed in mountain sports, with strong background in rock climbing, alpine climbing, ski mountaineering, she brings a deep and well-rounded expertise to her guiding. Born and based in Coyhaique, in Chile’s Aysén Region of Patagonia, near the majestic Northern Patagonian Ice Field, María Paz has dedicated her life to the mountains and to science education. As a geologist, she enriches her guiding with insights into the geological history and formation of mountain landscapes, offering a deeper, more meaningful experience for her clients. She also contributes her expertise as an educator in an conservation-focused study abroad program, combining her passion for nature, science, and outdoor leadership.
Marco Gabrielle Calamaro
With a spirit forged in the Andes and a passport full of remote peaks, Marco is a mountain guide who lives and breathes adventure. Marco is a certified UIMLA mountain leader from Uruguay with over a decade of experience guiding in high-altitude environments across South America and beyond. Based in Mendoza, Argentina, he has led numerous expeditions in the Andes, including over 17 seasons in Aconcagua, as well as guiding in the Cordillera Blanca (Peru) and Denali (Alaska). Marco is known for his technical expertise, calm leadership, and deep knowledge of mountain safety, holding multiple certifications in rope access and remote medical response. He is the kind of guide you want by your side when the trail disappears and the real journey begins.
Sustainability
At Arista, sustainability shapes every trip...
We follow Leave No Trace principles: we stay on established routes and follow one simple rule, everything that goes up comes back down. Every trip begins with a briefing on how to move through the mountains without leaving a trace.
We are working to eliminate single-use plastics, we use water and fuel carefully in camp, and we repair our gear before we replace it.
We respect the history, culture and sacred sites of every region we visit, and we work with local guides, arrieros, mountain huts, drivers, cooks and small businesses through fair, long-term relationships, so that what you invest in your trip also strengthens the communities that welcome you.
We are equally committed to fair, safe working conditions and ongoing training for our own team.
Along the way we share what science teaches us about the places we visit, because understanding how a volcano formed or why a glacier is retreating is the best way to learn how to protect it.
We are committed to provide logistics for glaciological, geological and climate research, supporting the science that helps protect these landscapes.
We review our policy every year and are currently working toward Chile’s S Seal for sustainable tourism, awarded by SERNATUR.