Fujian Tulou Museum gives useful background on the region's round and square earthen houses before you visit the main tulou clusters. Exhibits explain how the buildings were planned, defended, and lived in by Hakka communities.
The museum is in Yongding's main town rather than beside the famous clusters, so it works best at the beginning or end of a tulou route. It is a practical stop for travellers who want more context than the village sites alone can provide.