Yup, Lake Tahoe. Amazing place. Incredible views, incredible water (chilly, but as clear as pool water) and big enough to have so many great spots to hang out in and still "explore".
Yup, good guess...Tahoe. My favorite place on the planet. Huge snowfalls this past winter so the lake is now full too. Cruising and swimming in water so clean you could drink it is such a great experience.