Alongside Lukkarinmäki and Moisio, the Kauniainen area was annexed to Salo from Uskela in the early 1930s. Originally, this area of fields and meadows belonging to Joensuu Manor was almost unbuilt until the 1920s, when one-storey log houses were first built in the area owned by the Kauniainen estate. They were later followed by one-and-a half-storey log houses. The heart of Kauniainen developed into a unified and pleasant area of single-family homes, which was defined as a built cultural heritage site of national significance by the Finnish Heritage Agency. Since the 1960s, urban development has affected the area. The original character of the wooden house area has been changed by the apartment blocks and the complex of three educational institutions in the north-west, the construction of supermarkets on the eastern edge, and the construction of the block between Turuntie and Helenankatu, as well as the buildings offering assisted living facilities.