Significance StatementPeople engage with nature in a range of ways, including sharing their experiences, values and concerns about specific landscapes on social media. For instance, on Twitter, governments, news, conservation, management, tourism and other organizations, as well as individuals share short 280-character microblogs (tweets) about a range of issues. We assessed public debate on Twitter about the Blue Mountains National Park in Australia to illustrate the benefits, but also limitations and concerns with the use of this, still novel, method for public engagement. Using a quantitative analysis of the tweets-content we identified common topics and emotions, including similarities and differences between the tweets posted by Australians and those from other countries regarding this globally important and popular mountain landscapes.