If you're into the physical infrastructure of the Internet then this map should be your starting point. The Submarine Cable Map is a free resource from TeleGeography. Data contained in this map is drawn from Global Bandwidth Research Service and is updated on a regular basis. The map is rich of information including cable capacity, provider name and other elements; however, the cable routes on the map do not reflect the exact physical location.
View the map here - http://www.submarinecablemap.com/