Where were atom bombs invented?

London, by Leo Szilard in 1933

It took 12 more years to discover suitable materials and build the industrial infrastructure to prepare those materials, before they could be built.
London by Leo Szilard in 1933. However it took 12 years and thousands of workers to make the invention into a workable weapon in 1945.
A-Bombs were developed within the Manhattan Project which was part of the Los Alamos National Laboratory located in Los Alamos , New Mexico .