Outdoor pool closedPlease note a minimum age requirement applies to most US hotels. In many hotels the primary guest must be at least 21 years of age on the day of check-in.Pool facilities are closed. Guests can use the swimming pools from a hotel nearby.Resort Fee: Unless otherwise stated hotels may charge a resort fee payable directly to the hotel by the guest. - Important Information: Please note a minimum age requirement applies to most US hotels. In many hotels the primary guest must be at least 21 years of age on the day of check-in. For some hotels the minimum age is 18. Upon check-in photo ID may be required. You may contact our call centre prior to booking to confirm whether restrictions apply. - Important Information: Please note that Hilton Union Square is undergoing a waterproofing project (Caulking the windows) on the exterior of the building. The project is moving from one side of the building to another. Currently it is on O’Farrell Street and will move to Mason Street in January, then to Ellis Street (approximately 2 months per side weather permitting). Work is being done, Monday-Friday from 9am-5pm. There is no noise and no obstruction to guests. There is scaffolding being placed under the main entrance canopy and it will be moved at the end of November. - City Tax: San Francisco hotels charge a nominal daily City Tourist Tax directly to the customer. Local regulations state this must be collected by the hotel and cannot be prepaid. Please don’t hesitate to contact our call-centre if you require further information. - Important information: Please note that the 16th Floor outdoor Pool and the pool deck will be closed for renovation. Working hours: Mon-Fri 9:00-17:00.Scaffolding/Facade refurbishment