MTA Building, Government skyscraper in Downtown Los Angeles, United States

The MTA Building, also called One Gateway Plaza, is a 398 ft (121 m) office tower east of Union Station across the tracks, at the Patsaouras Transit Plaza. McLarand Vasquez Emsiek & Partners designed it with 1930s Hispanic-Deco and post-modern references, Italian granite and English brick; its main boardroom seats 350 and a 26,495-litre aquarium stands inside.

Designed by McLarand Vasquez Emsiek & Partners and completed in 1995 at a cost of $145.5 million, the tower was criticized before opening as a public-agency "Taj Mahal" for its Italian granite, English brick and $300,000 aquarium; supporters argued it would spur development around Union Station. It housed the Southern California Regional Rail Authority (Metrolink) from 2011 to 2018.

The tower's design mixes 1930s Hispanic-Deco and postmodern influences, with Italian granite and English brick on the facades. Critics called it a "Taj Mahal" for a public agency, citing a $300,000 aquarium in the lobby. Proponents argued it would spur development around Union Station and create a public gathering place.

The building sits at a junction of major transit corridors, making it easy to reach by bus or train. The location means the area tends to be busy during weekday business hours and quieter in the evenings and weekends.

The building's construction was filmed for the 1994 children's video There Goes a Bulldozer, in which Dave Hood climbed a tower crane on the site. A digitally altered image of the tower later stood in for the 1996 headquarters of villain Henry Starling in the Star Trek: Voyager episode "Future's End", and a matte painting of it appeared as a building on the Mari homeworld in the 1997 episode "Random Thoughts".