The Son Bhandar Caves, also Sonebhandar, are two artificial caves belong to Jainism (to Ajivikas earlier) are in Rajgir in the state of Bihar in India.
The caves are generally dated to the 3rd or 4th century CE, based on the dedicatory inscription found in the largest cave which uses Gupta script of the 4th century CE, although some authors have suggested the caves could actually go back to the period of the Maurya empire from 319 to 180 BCE. The main cave is rectangular with a pointed ceiling, and the entrance is trapezoidal, reminiscent of the structure of the Barabar Caves (the first artificial caves of India, dated the 3rd century BCE). The quality of the Mauryan polish and the finish are nevertheless much inferior.
An inscription in the rock at the entrance of the cave in Gupta characters of the 4th century of our era mentions the construction of the cellar by a Jain Muni ("wise man") named Vairadeva. This inscription naturally led to date the cave to the same period of the 4th century CE.
According to Gupta, however, this inscription may be ambiguous and, for him, might only mean that the cave was the subject of re-development work at that time. For this reason, he tends to date the cave on the basis of its similarities with the caves of Barabar (general shape, trapezoidal entrance door, polishing, although extremely limited) to the time of Ashoka (260 BCE), or even a little earlier, making it the possible precursor of all artificial caves in India such as the Barabar Caves.
The cave dates were built during rule of Maurya empire during 319 to 180 BCE.