Tongtianyan (通天岩) is a Buddhist grotto complex about eight kilometres north of Ganzhou, where the cliffs of a valley have been carved with over 300 figures across a series of niches and cave chambers. The carvings span from the Tang dynasty through the Song and into the Ming period, and the stylistic differences between periods are visible if you know what to look for — the Tang figures tend toward greater naturalism; the Song examples are more stylized and frontal.
The site is set in a narrow wooded gorge with a stream running through it, which makes for a pleasant walk regardless of your interest in Buddhist iconography. A stone pathway links the main carved areas and the inscriptions from Song-dynasty scholar-officials (including Su Dongpo, who visited in the eleventh century) are carved into smooth rock faces throughout. Allow ninety minutes. Buses run from Ganzhou's central bus station.