Klaten sits in the flat, fertile country between Yogyakarta and Solo. Many travelers pass through it on the main road or train line, but the regency rewards a slower day with old temples, rice-field views, and spring-fed swimming pools that are part picnic spot, part local ritual of cooling off.
The best-known ancient site on this side of the plain is Candi Plaosan, a Buddhist complex close to Prambanan but quieter and more atmospheric in the late afternoon. Klaten also has smaller temples such as Candi Merak, where the reward is not scale but the sense of finding a 10th-century shrine still sitting in village country.
Water is the other reason to come. Umbul Ponggok is the famous clear spring pool, with fish, underwater photos, and a carnival feel on busy days. Rowo Jombor and the Pusur river tubing scene make the day less temple-heavy, especially if you are travelling with local friends or children.
Klaten works best as a side trip from Yogyakarta or Solo. Start early for the temple plain, take a long lunch, then save the springs or Rowo Jombor for the hotter part of the day.