Fontanka. The Fontanka, a left branch of the river Neva, flows through the whole of Central Saint Petersburg, Russia ??? from the Summer Garden to Gutuyevsky Island. It is 6.7 kilometres (4.2??mi) long, with a width up to 70 metres (230??ft), and a depth up to 3.5 metres (11??ft). The Moyka River forms a right-bank branch of the Fontanka. Lined along the Fontanka Embankment stand the former private residences of Russian nobility.