Polonnaruwa with the audio map or hire a guide is the guide worth it

Honest answer: depends on how much you care about context. The Polonnaruwa archaeology free map plus the audio guide (downloadable from the official Department of Archaeology app, around 1000 LKR) is genuinely good - it tells you what you are looking at and gives a basic timeline. For visual-only travelers it is enough. A LICENSED guide for the day (around 40-60 USD) adds value if: (1) You want to understand the political-religious story of why the capital moved from Anuradhapura, (2) You care about iconography (which Buddha posture means what, why a stupa is shaped as it is), (3) You want the small-detail catches in the Vatadage and at Gal Vihara that 95 percent of tourists walk past. Splurge-decision: if Polonnaruwa is the only ancient capital you will visit on the trip, get the guide; if you also have Anuradhapura and Sigiriya, the map is fine for Polonnaruwa and you splurge on a guide elsewhere.