Geneva 15.7%. Of the agricultural land, 0.3% is used for growing crops. Of the water in the municipality, 0.2% is composed of lakes and 2.9% is rivers and streams. The altitude of Geneva is , and corresponds to the altitude of the largest of the Pierres du Niton, two large rocks emerging from the lake which date from the last ice age. This rock was chosen by General Guillaume Henri Dufour as the reference point for surveying in Switzerland. The second main river of Geneva is the Arve, which flows into the Rhône just west of the city centre. Mont Blanc
Transport in the European Union considers that an "urban" road around a city can be considered as an "express road" even if those roads do not form part of the network of main international traffic arteries or are located in urban areas when it matches with its definition provided in point II.3 of Annex II to the European Agreement on Main International Traffic Arteries (AGR), signed in Geneva on 15 November 1975. The EU currently cooperates with the European Space Agency, which is expected to become an EU agency in 2014. One of their projects is the satellite navigation system Galileo. Transport in the European