This postcard shows the last station of Warsaw Suburban Railway, which is in Grodzisk Mazowiecki. Grodzisk Mazowiecki is a town in central Poland with 26,881 inhabitants (in 2006). It is located 30 km southwest of Warsaw.
Warsaw Suburban Railway (WKD; Warszawska Kolej Dojazdowa) is a suburban light rail line in Poland's capital city of Warsaw. The line, together with its two branches, links Warsaw with the municipalities of Michałowice, Pruszków, Brwinów, Podkowa Leśna, Milanówek and Grodzisk Mazowiecki to the south-west of Warsaw.
The line was opened on 11 January 1927 as Elektryczna Kolej Dojazdowa (Electrical Suburban Railway), and received its current name in 1951. It was the first electric railway in Poland and the first one with automatic colour light signalling, supplied by the Swedish firm Signalbolaget.
The stamp on the left is from a set of 3 stamps issued in 2002, representing Polish cities, this one here being the Cathedral of Gniezno, showing the coffin with relics of St Adalberg. I couldn't find any info about the second stamp but it was issued in 1999.