Advice to tourists: There is a "tourist train" (Tren de la costa), which is promoted as an alternative to the regular train from Retiro station. You start from Retiro anyway and change at Olivos to the light-rail Tren de la costa. It is described as more modern, scenic and comfortable alternative to the regular train, allowing the option of getting off at the intermediate stations like San Isdro for shopping or sightseeing. DON'T DO IT. The train is packed solid and if you managed to get off you would never get back on. The regular train from Retiro is faster and cheaper and you get a seat. It rattles a bit but is quite O.K. (We came back that way.)
Some of the pictures here were taken from behind the driver of the train, most were taken on a one-hour tourist boat cruise from Tigre up Sarmiento River. Worth doing.