The Archaeological Museum at Bodh Gaya houses a collection of Buddhist and Brahmanical antiquities recovered from the site and its surroundings, mostly belonging to the Pala period (8th to 12th centuries). The Palas were the last great Buddhist dynasty of India, and under their patronage Bodh Gaya became one of the foremost centres of Buddhist scholarship and art in Asia.
The collection includes carved stone railings, votive stupas, sculptures of bodhisattvas, and inscriptions that document the history of the Mahabodhi Temple complex over more than a millennium. The railing panels in particular give a sense of how richly ornamented the site once was. The museum is small and can be covered in under an hour, but it provides useful context for understanding what you see at the temple itself.