Re: Places with great cache density
I hesitate putting the words 'great' and 'cache density' in the same sentence
but seriously, almost every major Western capital city will give you pretty full-on cache density these days. The bigger the population, the moreso. Add in a tourist destination (eg. London, Paris, etc) and you'll ramp that up even further.
Germany's pretty loaded too in terms of overall density, and the US is probably your powertrail HQ - especially Nevada.