DotNetNuke uses "Solparts Menu" as default navigation module. Unfortunately it generates a lot of "bad" tables.

Please have a look at the tutorial if you'd like to use the default navigation provider.

We recommend to use 3rd-party module, for example Snapsis.

Advantages of CSS NavMenu by Snapsis:

• semantic code (navigation list) 
• a lot of templates (Flyout, Dropdown, Tabs...)
• maximum control through a template system
• optimized for search engines