The world's tallest hotel, Ciel Tower, is indeed scheduled to open in Dubai in 2025. It will be located in Dubai Marina and will be a part of the Vignette Collection by IHG Hotels and Resorts. The tower is expected to feature over 1,000 rooms and apartments. 

Here's a more detailed look at the project:

Ciel Tower will stand at 365 meters (approximately 1,200 feet). It will house 1,042 rooms, including 150 suites, spread across 82 floors.  The project is being developed by The First Group. The architectural firm behind the design is NORR Group Consultants International Limited. Besides the impressive height and number of rooms, Ciel Tower will also boast a sky pool, a sky restaurant, and a sky garden.

While the exact date is not yet specified, it is expected to open in late 2025.