"Built in 2016, Katena takes its name from the catenary curve - the shape of a chain suspended between 2 points. Gaudi used suspended chains when he designed the Sagrada Familia. The catenary has a visual sympathy with pneumatic forms and in Katena. Entering the airlock provides the first encounter with the catenary as the airlock windows are in the form of the inverted catenary. Proceeding then to the first of the 3 dodecahedral domes the catenary makes its appearance as a motif generated by displaced seams. Catenary curves may be found elsewhere in the structure – altogether there are more than 100. Photo by Roto Studios. From the Architects of Air homepage: "The Main Dome of Katena is said to resemble a pineapple and has been likened to a Hindu temple from the inside. Its construction was particularly intricate with a fine mesh of riveted and sewn reinforcement defining the shape and over 200 colour spots swirling upward to a green finial."