The modern archaeological museum near the main entrance was funded by UNESCO and is one of the best of its kind on the island. Glass cases display bronzes, ivories and ceramics from the excavations, and large-scale models reconstruct the major buildings as they stood when complete — useful before you walk out among the ruins.
Half an hour is enough to absorb the key rooms. The model of the Vatadage with its timber roof is particularly worth looking at, as is the display of Polonnaruwa-period bronze Hindu deities — the legacy of the Chola conquest and the resurgent Sinhalese state's enthusiasm for South Indian art.