During a brief visit to Austria last year I managed to find a few more pile dwelling sites:

Attersee: On the lakefront at Seewaldchen there is a mock-up of a pile dwelling with descriptive signs. Opposite the railway station , beside the lake in Attersee village is a descriptive sign. At See am Mondsee there is a descriptive sign, and piles are visible beneath the water from the nearby bridge. I reached these sites by bus from Vocklabruck.

Keutschachersee: I found a descriptive sign at the eastern end of the lake, near the entrance to a recreation area. I caught a bus there from Klagenfurt.