The historic Union Depot in St. Paul is back in service today, with Metro Transit buses being the first tenants to use the newly-renovated facility. Amtrak will move its Twin Cities operations to Union Depot in early 2013, and the facility will also be a Central Corridor Light Rail Transit stop when that line is finished in 2014. The depot -- in the midst of a $243 million renovation -- was built by railroad baron James J. Hill in 1923.