Opened to traffic in 1943, the Howrah Bridge kolkotta India (officially called the Rabindra Setu, after renowed Bengali poet Rabindranath Tagore) crosses the Hooghly River to link Kolkata with its twin city of Howrah on the other side. Approximately 150,000 vehicles and 4,000,000 pedestrians use the bridge each day. The most impressive thing about this bridge is that it crosses the river in a single span, without any pylons connecting it to the river bed. It's one of the longest bridges of its type in the world at that time. To get a feel for why the Howrah bridge is also said to be the busiest bridge in the world, you really must walk across it. It's only then that you'll truly get to experience the sheer volume of traffic that it carries -- including cars, buses, bicycles, bullock cars and innumerable people bearing loads of heavy wares on their head. The traffic makes fascinating viewing .