The way Onsen is laid out makes it quite an unusual flat. You have two separate suites, each with its own kitchen (and each available to rent individually), which share a small courtyard. It’s the kind of place that, if misjudged, could be quite soulless, but luckily that’s not the case here. The design, heavy on plants and nods to Japanese culture, fits the space perfectly, and amplifies the brightness and sense of space. And while there isn’t much entertainment on offer (most notably, there’s no TV), the streets of Monti outside should provide all the entertainment you need.