sentences:  Today, there are more 342 bridges over canals and rivers of various sizes, styles and constructions, built at different periods.Some of them are small pedestrian bridges, such as Bank and Lion bridges, others are huge transport arteries such as almost one kilometer long Alexander Nevsky Bridge.There are about 800 small bridges across hundreds of smaller ponds and lakes in public parks and gardens, and over 100 bridges in various ports, marinas, yacht clubs and private industries.