The airport in Kaliningrad (formerly Königsberg/East Prussia), on a 15,100 square kilometers Russian enclave surrounded by EU countries, is seeking permissions to implement the "Open Skies" agreement, to be able to increase the traffic to 5 million pax annually and to become a transit hub for flights between Europe and China. Right now it's undergoing the vast enlargement and development works under a concept developed by Netherlands Airport Consultants B.V. backed by the investment in the range of $100 million. A few more details
here.