The function of this architecture is security and controlling all the floodgates located at port of Fukura, enlighten dangerous of the Tsunami for tourists, and use as a place of refuge in case of the Tsunami warning. For these reasons, ensure to keep the spaces of necessary and viewpoint for watching all over the port, also rational shape and structure to against of Tsunami and the drift came after disaster are necessary. Main floor is placed higher level than assumed height of tsunami and opening the ground level floor allowed when waves passing through. Make the outside wall curved as efficient form to disperse stress. This form consists of 7.3m width belt (curved wall); continuous arcs are constructer and crossing by 6 different center of circle. Consequently, these arcs are closing at the same point both start and finish.