While for years Metro has refused to sell ad space on buses and trains, recently Houston Zoo advertisements have been featured on the side of a metro train.

The No. 1916 steam engine left the zoo April 1, but zoo visitors will still have several chances to ride the train as it's pulled by the No. 1924 engine before it leaves on Oct. 31.

Also think about popping into Zoo Lights at the Houston Zoo. In addition to the awesome mechanical light displays and the chance to see some of the animals at night, Zoo Lights has a small train ...