1. Lake Brienz, also known as Brienzersee, is a picturesque lake located in Interlaken, Switzerland. The lake offers stunning views of the surrounding mountains and is known for its crystal-clear, turquoise blue water. One of the interesting facts about the lake is that it is fed by glacial meltwater and is up to 260 meters deep. The lake is also home to a variety of fish species, including brown trout and lake trout, making it a popular spot for fishing enthusiasts. Visitors can take a boat tour of the lake or take a dip in its refreshing waters during the summer months.

2. Lake Brienz is open 24 hours a day, 7 days a week. There is no specific phone number for the lake, but visitors can contact the Interlaken tourism office for more information at +41 33 826 53 00.

3. There is no admission fee for Lake Brienz, but visitors may need to pay for parking if they are driving. There are several public transportation options available to reach the lake, including train, bus, and boat. Visitors can purchase tickets for boat tours at the Interlaken boat station or book in advance online through various tour companies.