For past several years the National Heritage Board of Poland has been studying and documenting the most valuable historical monuments in Ukraine, part of the joint cultural heritage of the two countries. A successive convention has been signed in Lviv on 10 October 2007, rendering precise mutual obligations and defining future joint ventures. The planned documentation involved a photogrammic record of the elevation of the castle in Zolkiew and a photographic documentation of residences in Podhorce, Pomorzany, Olesko, Zloczow, and Brody. Other tasks included a dendrological inventory of the park in Zolkiew and cultivation instructions concerning the park in Podhorce. The Polish visitors also searched for written and cartographic sources in assorted Lviv archives. The outcome of the stay will be made available to the Ukrainian side and shall serve the National Heritage Board for further studies on the protection of the joint cultural heritage of Poland and Ukraine.