Martha C.
Google
These ruins are important in Lanna, then Siam history, and the best part is you can do them yourself and take your time!
I took a taxi down from central Chiang Mai, then chose to walk the ruins for several hours. (Full disclosure, I’m a historian!) Beyond the info center - which should be your starting point - there’s little info. You can, however, find several good info sites online to have with you.
Several of the ruins are part of modern temples as well, with much more to see and drinks/toilets available. I chose to walk, but you can also rent bikes for a slower tour. Personally, I enjoyed seeing the surrounding residential area and chatting with locals. For those short on time, you can choose a horse and buggy or electric tram.
Whatever you choose, this is certainly a site with seeing - and there’s lots of ongoing construction as the various sites are upgraded. (But be warned, I expected a stray taxi or tuk-tuk at the closest temple to town, there was nothing. Just be prepared with Grab!)