What is the fine-grained topic of the following text: With the Royal Melbourne Exhibition Buildings listed on the World Heritage Register on the basis that it and the Eiffel Tower are the last substantial reminders of the great nineteen-century Expositions Universelles, it is timely to reflect upon the history of this palace of stucco and glass and its long practice of displaying design objects. Only return the topic.
The history and significance of the Royal Melbourne Exhibition Buildings.