This article explores the linguistic landscape of social media posts associated with specific geographic locations using computational methods. Because physical and virtual spaces have become increasingly intertwined due to location-aware mobile devices, we propose extending the concept of linguistic landscape to cover both physical and virtual environments. To cope with the high volume of social media data, we adopt computational methods for studying the richness and diversity of the virtual linguistic landscape, namely, automatic language identification and topic modelling, together with diversity indices commonly used in ecology and information sciences. We illustrate the proposed approach in a case study covering nearly 120,000 posts uploaded on Instagram over 4.5 years at the Senate Square in Helsinki, Finland. Our analysis reveals the richness and diversity of the virtual linguistic landscape, which is also shown to be susceptible to continuous change.