We spent a couple of days at Borobudur. This is a well-restored Buddhist temple from the 9th century, when Buddhist and Hindu traditions tended to mix in this region. It's not as large as Angkor Wat (main temple) but its detailed carvings are better restored. It's best to visit the site at dawn, when it's a bit cooler, the light is better, and you beat the crowds. (Whether it's worthwhile to pay extra for the pre-dawn visit, I couldn't say). After 4 pm is not bad, but they start chasing you out by 5.

A half-day is really enough time to see the site, but we had a pleasant and relaxed couple of days
We stayed at the Manohara Hotel, which is attached to the monument . I liked this garden-set hotel for its tranquility and proximity to the site. There is a hill inside the temple site which gives good views and was empty of people on the afternoon we were there. I wouldn't cycle on the main roads, but there are a lot of smaller paved roads and unpaved lanes without much traffic, which would be interesting to explore.

We got up early on our last morning, and on our way to the Yogyakarta airport for our early-afternoon flight, we arranged to visit Prembanan, an impressive Hindu temple complex from the same era. We also stopped at three other lesser temples, of many in the region, which we could have skipped.