San Diego Marriott Gaslamp Quarter operators plan a mid-December opening for City Sights, a glass-enclosed balcony venue being added to the hotel’s rooftop Altitude Sky Lounge.

Operators said the new indoor venue, on the hotel’s 22nd floor, will provide nearly 360-degree views of the surrounding downtown, and host year-round gatherings. Project costs were not disclosed.

The balcony, on the north side of Altitude Sky Lounge, will include glass sliding doors, its own bar, high-top communal tables and modern modular furniture that can be adjusted for special events and bookings.

The 306-room hotel is at 660 K St.

— Lou Hirsh