It is very difficult, even for architects and builders, to think effectively in 3D. The jump from a 2D set of drawings to actual 3D spaces with all the complexities of construction is challenging. Models are a fantastic tool to bridge this gap. There are very good modelling programs available, but actual built-by-hand models are also a great design tool. The photos are of a very large model that was built by Antonio Gaudi’s studio for the Sagrada Familia church in Barcelona. It is an almost comically complex building and likely would have been impossible to build without models.