A local El Calafate agency running the excursions to the Perito Moreno glacier, including the minitrekking on the ice, and the other standard trips out of town. Being based in Calafate rather than selling from Buenos Aires matters here: the glacier trips depend on weather and lake conditions, and a local office is the one that tells you the morning of.
The pin sits on Puerto San Julián at street level. Book by WhatsApp.