A significant amount of the lighting in the large tanks (oceanic, open sea, lagoon, sea lions, submerged forest, penguins, etc.) is natural (windows and openings in the roofs) and therefore, follows the seasonal and lunar cycles. Additional lighting controlled by timer is provided by special lamps (increasingly by LED). There is even a blue night light that mimics the moonlight. The "scenic" lighting is switched off at night. Therefore, only natural moonlight passes through the openings above the large High-Seas tank.