Parque Nahuel Huapi ’s focal point is its namesake lake, whose fingerlike channels converge near the Llao Llao peninsula to form the main part of its 560-square-kilometer surface. With a maximum depth of 454 meters, it drains eastward into the Río Limay, a Río Negro tributary.
In the middle of Nahuel Huapi’s northern arm, Isla Victoria once housed the APN’s park ranger school (since relocated to Tucumán), which trained rangers from throughout the Americas.
From Puerto Pañuelo, Turisur’s Modesta Victoria (Mitre 219, tel. 02944/42-6109, www.turisur.com.ar ) sails to the island (US$35 plus US$7 national park entry fee) at 12:15 a.m. while the Cau Cau (Mitre 139, tel. 02944/43-1372, www.islavictoriayarrayanes.com , US$36 plus US$7 national park entry fee) goes at 2 p.m.; both continue to Parque Nacional Los Arrayanes  (which is more accessible from Villa la Angostura  on the north shore). Bioceánica Turismo (Avenida San Martín 484, tel. 02944/43-6240, www.bioceanicaturismo.com.ar , US$32) sails at 9 a.m. and 1:30 p.m.