Our research group has been working in the area of Ontology Engineering for more than two decades. Most of our initial work focused on the proposal of ontology engineering methodologies, methods, techniques and tools, which were normally applied for the development of single ontologies and for ontology networks for specific organisations or domains. This work has continued evolving with adapted methodologies and methods, with new tools and services that cover more parts of the ontology development lifecycle, and especially with the need to setup a more holistic view into how sustainable ontology development efforts need to be tackled and organised in those cases where multiple stakeholders are involved.In this talk, I will describe our experiences in setting up ontology governance models in this context, with a special focus on our work in the Ciudades Abiertas (Open Cities) project, where we are developing a network of ontologies to homogenise the open data that cities are publishing so that they can create good quality knowledge graphs about their cities. I will reflect on the main challenges that we have faced, lessons learned (including good and bad practices) and our next steps for the proposal of ontology governance models for these types of contexts.