I've never come across a postcard like this--in the shape of a postage stamp with the edges perforated, so I was very pleased when it showed up in my mailbox. It came by way of a postcard swap via Swap-Bot. The picture shows the capital of Slovenia, Ljubljana. I'm not sure what the buildings are in the foreground, but the building atop the hill is the Ljubljana Castle which overlooks the Old Town. It dates from the 12th century.
And the stamp on the back of the card. It's from a series of Slovene fauna--these little guys are storks.