Hidden Tor services
Location Hidden Services are Internet services, including websites, who are only available using Tor or a proxy which accesses the Tor network and has been described as "All the popularity, cachet, and speed of The Web in '92". These websites and services have special domain names ending with .onion who can only be looked up by Tor's own DNS system.
 Why Location Hidden Services?
If you want to publish information about crimes done by your employer, your government or other information you do not want tracked back to you then Location Hidden Services is for you and you should learn HOWTO publish anonymously on the Internet using Tor and share your favorite subversive information.
Hidden services are identified by .onion domains, a DNS system built into Tor (which is only available using Tor).
It is interesting to note that if the Internet's normal root-dns servers (there is only a few of those) were suddenly shut down then virtually the whole web would instantly be unavailable.
Tor's .onion DNS system is actually much more robust and would still work even if Internet's root DNS servers were to be shut down.
 Accessing Hidden Services from the "normal" Internet
To access location hidden Tor services from the *normal* Internet, you can use a web service such as Tor2Web.
See HOWTO publish anonymously on the Internet using Tor to learn how to run your own location hidden Tor-service.