Complex sentence: The area was settled by the Walser people from the Valais who left behind characteristic "Walser houses", or "Stadel", buildings made of wood and stone sitting on short mushroom-shaped pillars.
Split into simpler sentences: The area was settled by the Walser people from the Valais. They left behind characteristic "Walser houses", or "Stadel", buildings made of wood and stone sitting on short mushroom-shaped pillars.