The Olivetti Dora portable typewriter (aka Olivetti Lettera 31, Ventura, Italia ’90 and Class, Underwood 315 and 310, Mercedes and Mercedes Super T, and Montgomery Ward Escort 33) is named for the Fiume Dora Baltea, a 110-mile long river in north-western Italy which runs through Ivrea, the home town of Olivetti. It is a tributary of the Po. It originates by Mont Blanc as the confluence of the Dora di Ferret, fed by the Pré de Bar Glacier in Val Ferret, and the Dora di Veny, fed by the Miage Glacier and Brenva Glacier in Val Veny. As it crosses the Aosta Valley, the Dora Baltea flows through the city of Aosta and near all the main cities of the lower Aosta Valley: Châtillon, Saint-Vincent, Verrès and Pont-Saint-Martin. After it enters Piedmont, it passes through Ivrea and a good part of Canavese and reaches the Po at Crescentino. It is popular place for whitewater rafting and kayaking. The Dora Riparia is another tributary of the Po.