Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

“Diver in Magic Kingdom”. Green Lake (Grüner See) is located Tragöss Austria. In spring snowmelt raises the lake level about 10 meters. This phenomenon, which lasts only a few weeks covering the hiking trails, meadows, trees. The result is magical to watch diving landscapes. Photo location: Grüner See at Tragöss, Austria. (Photo and caption by Marc Henauer/National Geographic Photo Contest)

In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

An array of colours dwarf visitors to the Rainbow Mountains in the Andes Cordillera in Peru in January 2023, which owes its colours to the minerals contained in the soil. The sulfur offers the yellow colour, iron oxide gives the red and copper sulfate is green. In total, it is made up of 14 different minerals. It was probably caused by weather and volcanic activity. (Photo by Guillaume Astruc/Naturagency/Solent News & Photo Agenc)

These stunning pictures of beautiful Icelandic waterfalls will take your breath away. The mesmerizing shots show the striking waterfalls set against the night sky and the hypnotic green glow of the northern lights, as well as the picturesque Icelandic scenery and stunning sunrises. Here: A mesmerising waterfall in the Icelandic country-side. (Photo by Arnar Kristjansson/Caters News)

The groom Paul Bellas and bride Heidi Coxshall will have a distinctive Shrek wedding. Few brides are willing to show themselves with green painting! The wedding is just because their 4-year-old son loves the movie Shrek, who’ll be a guest donkey on the wedding. The relatives and friends of the newlyweds are all dressed as roles in the Disney movie, such wedding is absolutely unique!

Pfc. Esmeralda Calderon stands and salutes the flag on the 15th green during the first round of the LPGA golf tournament at Kingsmill Resort and Golf Course in Williamsburg, Va., Thursday May 23, 2019. Pfc. Calderon, from San Antonio, Texas, is a Marine assigned to Naval Weapons Station Yorktown. (Photo by John Sudbrink/The Daily Press via AP Photo)

An infrared portrait from NASA's Spitzer Space Telescope which shows generations of stars is seen in this undated NASA handout image released February 14, 2013. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. (Photo by NASA/Reuters/JPL-Caltech/Harvard-Smithsonian/Handout)