This heatmap is created by Google, showing the most photographed places in the world. According to this, New York, Rome, Barcelona, Paris and Istanbul are the most photographed places in the world, in the mentioned order.
In India, the top places are Harmandir Sahib, the Red Fort, Jaipur, the Taj Mahal and the site of the 2008 Mumbai terror attacks.
The assessment is made on the basis of the photos shared via Google’s Panoramio service which is used to link photos and places on Google Earth and Google Maps.
But you can also say that if a place doesn’t look ‘hot’ in this map, the reason could just be that these services are not so popular in these areas!