Custom Event/Raid areas are going live with tonight's code push. Custom Areas provide a way for you to more precisely specify the location of raids/events using your own, events-admin provided info. You can set the title, a description, a URL to a map, and a URL to a screen shot for each location.
When adding or editing events, you will see a new drop-down under the current selector for game areas that will contain your custom ones. Any selection of a custom location will override any selection of a system-provided one. When adding a new area, if it's a game area you believe GP should include in the standard list, please check the "Share newly-added game areas" checkbox in your custom areas editor.
To get starting with this new feature, click the Edit button under your calendar and then click "Custom Areas."