In the period of May – June 2015, Dr Martin Lazar, a young Croatian mathematician from the Univeristy of Dubrovnik, visited the Basque Center for Applied Mathematics in Bilbao, Spain, in order to continue already established collaboration with its director, Professor Enrique Zuazua. Professor Zuazua is a distinguished international expert in Control Theory, a branch of Applied Mathematics. Dr Lazar had an opportunity to actively participate in numerous activities at the Center (seminars, courses, workshops, …), to present his previous results, as well as to get acquainted with the recent results and open problems of applied mathematics.