The task of this project was to develop a composite structure of capable withstanding conditions of the San Diego-Tijuana Estuary, while existing as a place to mitigate the tension present in the region. Through study of building tectonics and the organisation of the structure, a new form was derived from the structure logic of the arch and using tangency to develop a structural composition. The final structure exists as a permeable steel butterfly roof that allows for flexibility of program. The wide - spanning steel members are supported by concrete columns that anchor the loads