This card is my first card from Ukraine, sent by Helen, a student from Kiev. As Helen said, the square seen on this card is known under many different names but it becomes renowned as simply as "the Maidan", due to the political events that took place in 2004 after Ukrainan accession to independence. In French, it's called Place de l'independance.
Helen put four stamps of porcelain jugs on the card. Thank you, Helen! :D