The correct answer is - cirque.
A cirque (also known as coire and cwm) is valley with the shape of an amphitheatre formed by the erosion from the glaciers. The concave shape of the glacial cirques is open towards the downhill side, while its cupped part is very steep. On its three or more higher sides there's cliff-like slopes from which ice and debris go down and form the sides themselves. The floor of the cirque is characterized by its bowl shape.