Initiated in 2007, the INSPIRE Directive has set a legal framework to create a European-wide Spatial Data Infrastructure (SDI) to support the European Union (EU) environmental policies. This chapter analyses the INSPIRE infrastructure from a Big Geospatial Data perspective, describing how data is shared in an interoperable way by public sector organisations in the EU Member States and how it is made available in and accessible within the infrastructure. The INSPIRE Geoportal, which is the entry point to the whole infrastructure, is presented in detail. To justify its nature of a Big Geospatial Data infrastructure, the characteristics of INSPIRE data are mapped to those of Big Data's six 'Vs'. Despite many good results achieved in terms of data sharing, some challenges still remain related to data consumption from the user side. The chapter concludes with a dedicated discussion on how INSPIRE, and traditional SDIs in general, should evolve into modern data ecosystems to address these challenges while also embracing the modern practices of data sharing through the web.