Had heard about the Blue Lake (Kongleng) but never had the time to explore. Last week, while visiting a friend in Thakheak we decided that it would be a nice short trip and off we went in the 4WD. It's about 30 km north of Thakheak along Rd 13. Turn off to the east in Huay Aek (17 37.5799 N and 104 40.1789 E - there is only one largish dirt road right next to a small noodle shop). After about 2 km. turn right and follow the road which is generally good but in a few places narrow, quite steep and rocky. The lake (17 38.622 N and 104 48.829 E) is quite small but has an amazing blue colour as it is now dry season with most of the dirt having been washed out. The lake is 20-30 m deep and is apparently spring fed according to French geologists who investigated the source of the blue colour. Swimming is possible next to the Blue Lake (where swimming is not allowed) and you can camp there. The Blue lake itself has big fish swimming in it and according to the locals you can catch also quite big ones in the part where swimming is allowed. Considering the large number of signs in Lao and English around the lake, the Lao Tourism Authorithy has (had?) great plans for the area but unfortunately no signs on how to get there. All in all it took us about 5 hours including travelling and a pleasant picknick on the spot. It is very quiet out there - we were the only visitors and as a result there is no food nor drinks available (possibly in the nearby village Ban Nakheu).