I’m sorry, but as of my last knowledge update in January 2022, there isn’t any information available specifically about an observatory at the Marriott Harbour Hotel in Dubai. It’s possible that developments or new attractions have occurred since then.
To get the most accurate and up-to-date information, I recommend checking the latest sources such as the official website of Marriott Harbour Hotel, Dubai, or contacting them directly for details about any observatory or related attractions they may have.
If there’s another topic or location you’re interested in, please feel free to ask, and I’ll do my best to provide information based on my training data up to January 2022.