Tulou Country (土楼地区) is the rural belt where Hakka and Minnan earthen roundhouses — tulou — cluster by lineage along the ridgelines and streams of south-western Fujian. UNESCO inscribed 46 buildings in 2008 across three counties: Yongding (in Longyan prefecture, the Hakka heartland) and Nanjing and Hua'an (in Zhangzhou), the latter two a mix of Hakka and Minnan builders.
Read as a cultural landscape rather than a collection of monuments, the area is organised into ten inscribed clusters and standalones. Beyond the photogenic Tianluokeng, the essentials are Hongkeng (home of Zhencheng Lou, the "Prince of Tulou"), Gaobei (where five-ring Chengqi Lou earns the "King of Tulou" title), the hillside Chuxi cluster, and Hua'an's Qiyunlou (1371, the oldest surviving tulou).
Xiamen is the usual gateway. The Nanjing-County side sits ~1.5–2 hours out via HSR to Nanjing Railway Station plus a road transfer; the Yongding side is ~3 hours via Longyan. Most tulou are still inhabited, so a full day lets you fold homestays, tea stalls, and ancestor halls into what is otherwise a fortress-architecture tour.