There are several hot springs in the Annapurna region, but Tatopani during the Annapurna circuit trek and Jhinu on the Annapurna base camp route are the most popular hot springs with hot pool, where visitors can get in and enjoy the natural hot water. There is the Kaligandaki river close to Tatopani hot spring and the Modi river close to the Jhinu hot spring.
I strongly suggest you not go to the river like this because it is maybe dangerous. The rivers have narrow spaces with lots of rocks, so there is no chance of swimming if you slipped into the deep.
Please travel safely in Nepal!
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