Wiki Travel

Wikitravel is a project to create a free, complete, up-to-date and reliable world-wide travel guide. It uses MediaWiki to allow anyone to add information about destinations, activities, restaurants, bars, hotels, museums, etc. All the content is free under the Creative Commons Attribution-ShareAlike 1.0 license.

    http://www.wikitravel.org/

You can find comprehensive travel guide on http://www.traveliota.com