Represa San Jacinto is a large dam built along the river that runs through Tarija, Bolivia which has created a navegable lake. It's a very pretty area about 15 minutes from the city center and worth a morning or afternoon visit.
Here you can enjoy a fresh fish lunch throughout the day, beginning at about 9 am until the sun goes down. There are numerous local vendors along the shore. Some are just small huts and two or three actually have set up a roofed area with tables and chairs as "restaurants" right on the lakeshore overlooking the surrounding mountains and valleys. It's actually quite a good place to sample fresh grilled fish and tiny red crabs. About 15 different species of fish are served including Tarija's well-known dorado, along with other typical dishes such as chicharron. Be prepared to eat mostly grilled or deep fried foods along with sodas, cold beer, and delicious Tarijeño wine.
Represa San Jacinto itself is quite impressive. It's a mid-sized dam, which you drive or walk over, that empties into a deep gorge on the opposite side of the dam from the lake. The views from both sides are very pretty. You can actually take a row boat out onto the lake along the shore, just past the fish restaurants but no life jackets are provided. It's a nice place to spend a couple of hours enjoying the scenery and fresh air. For more places to eat and restaurants in Tarija click on the 'Food' link below. For more tourist attractions in and around Tarija click the 'Tours' link below.