Kościuszko Mound in Kraków, Poland, erected by Cracovians in commemoration of the Polish national leader Tadeusz Kościuszko, is an artificial mound modeled after Kraków's prehistoric mounds of Krak and Wanda. A serpentine path leads to the top, approx. 326 metres above sea level, with a panoramic view of the Vistula River and the city. It was completed in November 1823.
A lot of nice stamps:
Polish Alphabet, issued on 07.11.2006. Polish Cities - Sieradz , issued on 29.07.2005. Economy stamp, issued on 08.03.2013. Sunflower, issued on 26.06.2015. Cornflower, issued in 2015.