The 10 most radiation-polluted places on the planet

Source: http://brainz.org/ten-most-radioactive-places-earth/

Hanford, CT, USA - former Uranium/Plutonium factory for atomic bomb production --- etc ... with Chernobyl and Fukushima topping out the list at #2 and #1 respectively.

The list of locations are on land and surrounding either the factories for producing atomic materials, the former nuclear bomb test sites, or sites of nuclear power plant accidents.

Followup: http://climateviewer.com/2013/11/24/10-most-radioactive-places-on-earth/

This source made a somewhat more alarmist view on the list from brainz.org.  However, this one includes a lot of useful links to resource sites.