Views out over the Toktogul reservoir are sublime in the right light, and the first glimpse of it descending from the mountains on the Bishkek highway are quite memorable. There's no beach as such, but the shoreline is ok for swimming if you don't mind the 5km walk from the centre of town.
The reservoir was created in 1976 to power the dam downstream, which is still a major source of electricity for Kyrgyzstan and neighbouring countries.