Definitely rent a bike to go to visit monuments! Common rental price for bike 250-300 rupee. Also ride along the lake south to new town and back through rice plants!
Suggest u have your sunblock/sunglasses/pair of socks ready. As u have to take off your shoes at some religious spots, u'll have to go barefooted under the blazing hot weather in early Aug. US$25/tkt.
Have to cover your shoulders and knees (be prepared with a spare sarong), remove your shoes (the tiles are blistering hot though) and no hats... bring lots of water & sunscreen!
So far, the ruins of Polonnaruwa are the most interesting things I've seen in Sri Lanka. Just rent a bike because the area is pretty big and it would take days to explore it entirely by foot!
The size and scope of the ruined city is comparable to Rome, and some of the sites are remarkably intact. For that reason, if you have to choose here and between Anuradhapura, I'd choose here.
Al ser turístico y comparando precios es caro, pero merece la pena para cuando vas a lugares tan recónditos como Sri Lanka. Los monos algo cansinos, si das de comer a 1 prepárate casi para adoptarlo.