There's an error on the map.
The Polish village of Krościenko, where the Greeks were living, is situated on the Polish-Ukrainian border (https://goo.gl/maps/bn3hvDF1Xry). The map shows the larger Krościenko nad Dunajcem (https://goo.gl/maps/QXFai22Wy4C2), which is in fact the only result of Google search of the term Krościenko, but is not connected with Greek refugees in any way.
