General Alternatives:
* Website map
* Site structure
* Navigation map
* Content map
* Index
* Directory
* Outline
More Specific Alternatives:
* XML sitemap: For the specific file format used for search engine optimization.
* Hierarchy diagram: For a visual representation of the website's structure.
* Tree map: For a visual representation of the website's content organization.
* Breadcrumb trail: For a navigation element showing the user's current location on the site.
The best alternative will depend on the specific context and what you are trying to convey.