Map It! by Two Row Studio
by Two Row Studio on WordPress.org

Example page of how a post can be given map coordinates. Once saved, the marker can be dragged to a new location on the map to update the coordinates.
Map It! is a flexible, developer-friendly plugin to help take the tedious coding out of adding maps to a website that can mark geographic locations related to posts. The whole point is to let you choose the types of posts, the display and the formatting of maps markers and data to best fit your needs. Over time, more specific customization features will be made available to developers as well as extensions for the non-technical user to take advantage of the base plugin in new and useful ways.
If you are a developer and are missing a way to add a customization, drop us a line at support@tworowstudio.com so we can make sure we consider it for future releases.