Locate and click the main navigation menu (e.g., a hamburger icon or 'Menu' link) on the MGM National Harbor website to reveal the site's primary sections. Once the navigation is open, list all the top-level categories or links visible in the menu.
Carefully scan the entire current viewport for a hamburger menu icon (three horizontal lines), a 'Menu' text link, or any other small icon or text that typically indicates a site's main navigation. If found, click on the identified navigation element. Once the navigation menu is open, list all the top-level categories or links displayed within it.
The agent successfully identifies and clicks the main navigation element. The agent provides a list of all visible top-level categories or links from the opened navigation menu (e.g., 'Hotel', 'Casino', 'Dining', 'Entertainment', 'Spa', 'Meetings', 'Shopping', etc.).