Tansan Sengen Park

A small landscaped park in Arima Onsen, built around the town's carbonated spring source. The grounds are intimate: stone benches under maples, a covered wooden pavilion sheltering the well at the center, and bilingual signage explaining the source's history. The carbonated water itself can be tasted from a small drinking fountain; the mineral-heavy tang is sharp and metallic, and locals say it's an acquired one. The park is also the birthplace of Wilkinson Tansan, the carbonated water Japan's bartenders mix into highballs. Five minutes' walk uphill from Gin-no-yu.