The purpose of a transferium is to entice travellers into exchanging their cars for public transport for part of their journey. In this one, access unimpeded by tailbacks, car parking by means of a mechanical parking system and air-conditioned waiting rooms are designed to make the change-over process a pleasant experience. A ring of such transferia forms the trait d'union between the central city and the periphery, improving the accessibility of the central area and easing the pressure on city parking. The ring brings together large-scale programmes that would otherwise be out there in the periphery, at the same time making these accessible by public transport. This transferium in the Gemeenschapspolder stands at the intersection of two highways, the A1 and A9, where rail and road rub shoulders. At one side it registers as a boulder, honed smooth by a 'plinth' of infrastructure. On the other side it opens up to the panorama of the polder. The structural and spatial set-up makes space for a core of fixed programme components around which changing functions can be accommodated. Among the permanent functions are the 'crossover machine' with a subterranean car store and an international equestrian sports centre. The latter function will serve as the new economic carrier of the polder landscape. As a test of possible non-permanent functions, we have designed a patio hotel and a congress centre. In the node below the 'boulder' there unfolds the most generous of increments. Unprogrammed but indispensable, it gives a view out over the infrastructure: it is a place to meet and be met. Institution: TU Delft Tutors: Pi de Bruijn, Willem Hermans, Arie Krijgsman & Boudewijn Bach Specialization: architecture