Denver's Union Station is located in downtown Denver Colorado. It opened in the 1882 and once served over a hundred trains a day but now only two Amtrak trains east and west bound California Zephyrs and RTD light rail service. The station underwent a major renovation and reopened in 2016. Denver's Union Station is a very big part of Denver's history. It is the main railroad station for commuters coming in and out of the suburbs on the light rail system into downtown Denver. It also has a light rail system serving Denver International Airpot. Also known as DIA. It is also the main hub into Downtown Denver by light rail serving shops and restaurants in downtown Denver Colorado.