Google said the “use of Rich Snippets can help people find the web pages you’ve created that may reference a specific place or location.” Google added using these structured HTML formats will help Google “properly classify your site, recognize and understand that its content is about a particular place, and make it discoverable to users on Place pages.” This helps in two ways:
(1) Use structured markup to help Google identify the places mentioned on your site. If your site contains reviews or other information about businesses and organizations, then the structured markup helps precisely correlate your pages with the place mentioned.
(2) Tell Google about your content so that Google knows who you are and what content you have to offer if additional opportunities arise.
For more information on rich snippets as they apply to local search, see maps.google.com/help/maps/richsnippetslocal/.