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
Geneva Geneva) and 6.2% other Christian (mostly various other Protestants), 38% of Genevans are non-religious, 6.1% are Muslim and 1.6% are Jews. Geneva has historically been considered a Protestant city and was known as the "Protestant Rome" due to it being the base of John Calvin, William Farel, Theodore Beza and other Protestant reformers. Over the past century, substantial immigration from France and other predominantly Roman Catholic countries, as well as general European secularization has changed its religious landscape. As a result, three times as many Roman Catholics as Protestants lived in the city in 2000, while a large number of