In this February 1, 2017 photo, environmental activist Maruja Inquilla poses for a photo next to a Municipal waste treatment plant with water that flows into Lake Titicaca, in Juliaca, in the Puno region of Peru. “If the frogs could talk they would say, This is killing me”," said Inquilla, who recently showed up at the Puno governor's house carrying plastic bags filled with hundreds of dead frogs in protest. (Photo by Rodrigo Abd/AP Photo)

These otherworldly images give a rare glimpse inside caves barely ever seen by the human eye. With its peculiar pools of water and strange colored sediments, the bizarre looking tunnels of the Shakuranskaya cave could be a set straight out of a science fiction film. Found in the disputed region of Abkhazia, around 75 miles outside of Sochi, Russia, it is rumored the incredible underground chambers were formed after a huge earthquake struck the area in 1892. After causing part of a nearby mountain to collapse into the Amtkel River, it is thought the dam-like affect has created a series of interconnecting underground tunnels. Here: a large pool of water inside one of the tunnels. (Photo by Vladimir Mulde/Caters News)

Ra Paulette is an American cave sculptor based in New Mexico who digs into hillsides to sculpt elaborate artistic spaces inside mountains. Reviewer Martha Mendoza in the Los Angeles Times described the caves he created as shrines, as hallowed places, a “sanctuary for prayer and meditation” while others describe the caves as works of art. The caves are finished with “scallops, molded curves, smooth ledges, inlaid stones, narrow pods and crusty ledges”. His caves attract visitors worldwide.

Vardzia is a cave monastery site in southern Georgia, excavated from the slopes of the Erusheti Mountain on the left bank of the Mtkvari River, thirty kilometres from Aspindza. The main period of construction was the second half of the twelfth century. The caves stretch along the cliff for some five hundred metres and in up to nineteen tiers. The Church of the Dormition, dating to the 1180s during the golden age of Tamar and Rustaveli, has an important series of wall paintings. The site was largely abandoned after the Ottoman takeover in the sixteenth century. Now part of a state heritage reserve, the extended area of Vardzia-Khertvisi has been submitted for future inscription on the UNESCO World Heritage List

Boats of fishermen are seen on the dried Poopo lakebed in the Oruro Department, south of La Paz, Bolivia, December 17, 2015. Lake Poopo in Bolivia, the Andean nation's formerly second largest after the famed Titicaca, has dried up entirely. With the water now gone, animals have died off in the millions, according to studies. And the local families, having lost much of their sustenance, have been forced to migrate. (Photo by David Mercado/Reuters)

In this January 12, 2016 photo, an abandoned boat lies on the dried up lake bed of Lake Poopo, on the outskirts of Untavi, Bolivia. Drought caused by the recurrent El Nino meteorological phenomenon is considered the main driver of the lake's demise. Along with glacial melting, authorities say another factor is the diversion of water from Poopo's tributaries, mostly for mining but also for agriculture. (Photo by Juan Karita/AP Photo)