If you are looking for the quietest place, well off the tourist trail, then Muang Sui is it; just be prepared for no choices in accommodation and little choice of food.
The Nong Tang Guest House has a prime location on the western tip of the lake under the impressive limestone tower which dominates the area, but that's where the good things come to an end for this shabby and rarely used guesthouse. There is a bed (of sorts) and a mosquito net which is full of holes. The maid will bring some sheets, but they are certainly shy about cleaning them. The rooms are... Read our full review of Nong Tang Guest House.
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