NEW GUEST ROOMS. A new luxury offering in San Francisco, the JW Marriott Union Square has completed a multi-million dollar guest room renovation. Reap the benefits of a superb downtown location, luxury accommodations and brilliant amenities. Situated in San Francisco's thriving Union Square neighborhood, we offer travelers easy access to all areas of the city. Arrive at our hotel and immediately feel at ease in our spacious guest rooms and suites, which feature thoughtful details and modern amenities.