Postcard SI-98149 from Slovenia shows the Dolina Triglavskih jezer (Triglav Lakes Valley) in the Julian Alps in Slovenia. It is a rocky hanging valley above the tree line between the sheer sides of Mount Tičarica and Mount Zelnarica southwest of Triglav, the highest mountain in Slovenia and the highest peak of the Julian Alps at 2,864 meters or 9,396 feet.
The valley is also called the Seven Lakes Valley, although there are actually ten lakes in the valley. The lowest lake Črno jezero (Black Lake) is at 1,294 meters or 4,245 ft above sea level; the highest Jezero v Podstenju (Podstenje Lake) has an elevation of 1,993 meters or 6,539 feet. Each lake has a color varying from green, blue, brown to black.
I found this time-lapse video of a two-day hiking tour at the Triglav Lakes Valley on Youtube. The climbers made stops at Black Lake, at the beginning of their journey; at Big Lake next day, the largest and deepest lake also called Kidney Lake with an elevation of 1,831 meters or 6,007 feet; and near Green Lake at 1,988 meters or 6,500 feet, named after the algae living in the lake.