Thinking about, promoting, planning, building and preserving a healthy and quality urban environment that meets the needs of citizens and society is one of the main priorities of urban development. From this perspective, public open spaces (parks, squares, playgrounds, streets, riverfronts, etc.) are a fundamental common good and a key to providing a healthy living environment [
1]. As a physical space for social use, a public open space, henceforth POS, also acts as a place of communication, interaction, interaction and connection and is a common ground for cohesion and sharing, negotiation and contestation. POS define and structure, give character to the city, create meaning to the citizens, as it performs symbolic, memory and representation functions of urban life [
2,
3]. POS are defined by certain features (accessibility, leisure, engagement, etc.), each playing an essential role in improving the quality of the urban environment and social life and providing the
space for mobility, contact with nature, social, cultural and physical activities, and a diversity of daily and occasional experiences. As a stage for social life, it is thus important that POS is well-maintained, inclusive and accessible [
4]. The multidimensional nature of POS entails a dynamic and dialectical interrelationship between the social and physical environment, which influences practices, representations and experiences. As places of collectiveness, approaching, planning, producing and managing POS require different knowledge and the involvement of several disciplines [
5]. This collectiveness stresses the fact that a POS “speaks in the plural” and, as such “conveys an ambiguity of meanings” [
6] (p. 15). Hence, the features and performed activities bring the POS into focus of different disciplines. This, in turn, highlights the importance of inter/multi/transdisciplinary perspectives to approach, study and intervene in POS, and the pertinent adoption of participatory, collaborative and co-creative approaches [
5]. This brings us to the placemaking concept, the place-related identity and the collective re-imagination and reinvention of the spaces [
7] towards reshaping them for mutual benefits [
8]. Placemaking facilitates establishing innovative co-creation processes and use patterns, as it gives special consideration to the physical, cultural, and social identities that characterize a place and sustain its continuous development [
8,
9]. Furthermore, the engagement of the community, understood here as groups of stakeholders with shared interests and strong connection to their environment, implies involving a concerned group interested in actively provoking changes [
10]. It is therefore crucial to advance knowledge about how POS, as common goods, are developed, used, appropriated, experienced, perceived, imagined and represented. This calls on the flip side for a better understanding of people's spatial needs, their ideas and proposals for developing more responsive spaces [
3]. Encouraging cross-sector collaboration helps also to identify different ways to engage and get communities involved, also in managing and maintaining POS, thus paving the way to the sustainability and resilience of cities.
Backed by this multifaceted understanding of POS, also as a place for performing urbanity and citizenship and attach imaginaries, this paper focuses on the research ontology and methodology applied in different research projects that have in their core advancing knowledge on co-creation of POS and meeting people’s needs. Based on the learning acquired from the European projects - CyberParks and C3Places, and an Ibero-American project - Cyted RUN, this article aims to discuss the role of collaborative ethnography within the scope of participatory urban design and planning. The research in these projects, although varying in their aims and goals, hinge on four major common themes: co-creation of the public realm, engaging communities and stakeholders around urban places, generating a deeper understanding of the relationships between space (and environment), culture and society, and to underpin strategic, methodological, and planning recommendations. Overall, a collaborative ethnography approach can be seen as an umbrella platform under which these research projects and their activities emerge and overlap. This highlights the role of collaborative and co-creative methodologies for research towards informing policies for more inclusive, responsive and sustainable POS [
2,
3,
5]. To achieve this, research must embrace a wider concept and focus on ways to meaningfully engage people. Collaborative ethnography is used in this article to put field experiences into a wider perspective, to dialog together in the frame of these individual projects. It was used to articulate different techniques for collecting, analysing and evaluating data (for example, visual and field observation, interviews, questionnaires, etc.). This enables us to create a repository about people and their socio-spatial realities [
2,
5]. How such repositories were built in three projects (CyberParks, C3Places and Cyted RUN) along with their rationale are at the core of this article. On the basis of garnered lessons, we discuss the added value of collaborative ethnography for spatial research. To better understand the purpose of its use, a short description of the projects and their methodological approach are provided. Backed by the experiences gained with this process, we discuss the role of collaborative ethnography for participatory approaches, for placemaking and for informing urban design and planning policies.