Each year, millions of visitors flock to Angkor Wat, an ancient temple in modern-day Cambodia. There, they marvel at the 900-year-old towers, a giant moat and the shallow relief sculptures of Hindu gods. But what they can't see are 200 hidden paintings on the temple walls.

New, digitally enhanced images reveal detailed murals at Angkor Wat showing elephants, deities, boats, orchestral ensembles and people riding horses - all invisible to the naked eye.

Many of the faded markings could be graffiti left behind by pilgrims after Angkor Wat was abandoned in the 15th century. But the more elaborate paintings may be relics of the earliest attempts to restore the temple, researchers said. [See Photos of Angkor Wat's Secret Paintings]

In prehistoric Eurasia, drugs and alcohol were originally reserved for ritual ceremonies, and weren't used merely to satisfy hedonistic motives, a new study suggests. What's more, given the sacred role of the substances, their use was likely highly regulated and only available to elite citizens.

Many Eurasian cultures are known to have an ancient history with psychoactive substances, as evidenced by early written documents. The Greek historian Herodotus, for example, once described the Scythians' (Iranian equestrian tribes) post-funeral purification ceremony involving hemp, which dates back to the fifth century B.C.

But written records aren't the only indication of early drug and alcohol use.

"It is generally thought that mind-altering substances, or at least drugs, are a modern-day issue, but if we look at the archaeological record of prehistoric Europe, there are many data supporting their consumption," said study author Elisa Guerra-Doce, a prehistory expert at the University of Valladolid in Spain.

"Apart from the presence of macrofossil remains of plants with these [mind-altering] properties, there are artistic depictions of opium poppies, for instance, and some designs in megalithic tombs may have been inspired by altered states of consciousness."

Despite numerous indications, archaeologists have largely overlooked the use of mind-altering substances in Eurasian prehistory. So Guerra-Doce decided to sort through the scarce and scattered information in the scientific literature, in hopes of gaining a better understanding of the history and context of ancient drug and alcohol use.

She reviewed four lines of evidence: macrofossil remains of psychoactive plants, residues from fermented alcoholic drinks, psychoactive alkaloids (chemical compounds) on artifacts and skeletal remains, and artistic depictions of psychoactive plants and drinking scenes.

* Cave paintings were discovered in Vilafranca in Castellón, Spain

* They include drawings of two aurochs, two human archers and a goat

* A layer of dust protected 10 figures, which were exposed to the weather

* Computer analysis has revealed unseen details

Amazingly well-preserved cave paintings dating back seven millenia have been discovered in Spain.

The stunning murals provide a rare glimpse into daily prehistoric life - showing dramatic hunting scenes including human archers.

Despite being exposed to harsh weather, the 'totally unique' artwork has survived on a 19ft (6 metre) long wall inside a small cave in Vilafranca in Castellón, in the east of the country.

A group of students discovered a 7,000-year-old mummy during a trip to northern Chile, local media reported Monday.

La Tercera newspaper reported that the find was made by chance Saturday during a visit to the Morro de Arica site by local students.

The children, at-risk youths enrolled in an archeology workshop, were performing excavation work when one found a strange shape under dog droppings.

Remnants of a burnt ancient city, believed to be dating back to 2nd century BC, have been found in an archaeological site in Tarighat, nearly 30 km from here. The "gutted settlement" reminds one the famed Roman city of Pompeii that got buried under 13-20 feet of ash and pumice in the eruption of Mount Vesuvius in 79 AD.

The remains of the charred city have been found around 20 feet below Tarighat archaeological site which came into national focus when excavation had brought to surface a 2,500-year-old urban centre in 2013.

"It is a stunning discovery. Our excavation, which began last year, has reached 35 feet deep now. The excavation has so far yielded remains of various settlements that had come up at the site from sixth century AD to second century BC.

A new book released by NASA as part of the official NASA History Series examines the contributions that archaeology and anthropology can make to contemporary SETI (Search for Extraterrestrial Intelligence) research.

The authors draw analogies between deciphering the language and symbology of long-lost civilizations and decoding messages that may arrive from 'other worldly' origins.

The new book titled 'Archaeology, Anthropology and Interstellar Communication', edited by Douglas A Vakoch, Director of Interstellar Message Composition at the SETI Institute, is a collection of chapters by different authors who explore latest research regarding the search for extraterrestrial intelligence.

In the opening introduction, Vakoch sets out how the field of archaeology can contribute to this search:

"As we search for analogies to contact at interstellar distances, archaeology provides some intriguing parallels, given that its practitioners - like successful SETI scientists - are charged with reconstructing long-lost civilizations from potentially fragmentary evidence".

Anthropologist Ben Finney and historian Jerry Bentley draw a comparison between the decoding of ancient scripts, including Egyptian and Mayan hieroglyphics, and how we may be able to understand and possibly communicate with an extraterrestrial civilization, particularly through the 'universal language' of mathematics and astronomy. For example, when scholars began decoding ancient Mayan hieroglyphs, their earliest successes were in recognizing the basic numbering system used by the Maya, as well as their calendar systems, which were based on the visible motions of the Moon and Sun.

One of the oldest human skeletons in North America has been discovered by a team of international scientists in an underwater Yucatán Peninsula cave.

Named "Naia", the teenager fell to her death in a large pit called Hoyo Nego, meaning "black hole" in Spanish.

Patricia Beddows, a cave-diving researcher from Northwestern University, said: "The preservation of all the bones in this deep water-filled cave is amazing - the bones are beautifully laid out."

"The girl's skeleton is exceptionally complete because of the environment in which she died -- she ended up in the right water and in a quiet place without any soil. Her pristine preservation enabled our team to extract enough DNA to determine her shared genetic code with modern Native Americans," she added.

The skeleton, which is now covered in water, is estimated to be between 12,000 and 13,000 years old, suggesting Naia lived in the late Pleistocene or last ice age.

Archaeologists working at the Wari archaeological complex in the Vegachayoq Moqo sector have made new discoveries that promise to illuminate the mysterious pre-Inca society.

Mario Cueto Cardenas from the Ayacucho Culture Board told Andina that "Archaeologist [José Ochatoma Paravicino of the Universidad San Cristobal de Huamanga] presented a report and is preparing an exposition for the new Wari finds, which will allow us to explore unknown spaces, because [at the Wari site], we're just getting familiar with the citadel, there are more mysteries that will allow us to better understand their economic and cultural system."

Juan Arango Claudio, local tourism official, told Andina that "In spite of all the effort that has been expended, we only know a small percentage, that can't be more than 10%, about the Wari, but we're hoping that these advances will allow us more tourism flow, because these historical spaces are being evaluated."

Specifics about the new findings are expected to be announced in coming weeks, Andina reports.

The Wari were an expansive civilization that lived in Peru from around 500 AD to 1000 AD. Their capital city, also called Wari, was located near the city of Ayacucho, in inland Peru.

Turkish archaeologists excavating a harbor site on the European side of the Bosphorus have unearthed a 1,200-year-old wooden object which they claim is the ancient equivalent of a tablet computer. The device was a notebook and tool - in one.

The Byzantine invention was found within the remains of one of the 37 ships unearthed in the Yenikapi area of Istanbul, a site which has been at the center of excavations for the past 10 years.

Also known as Theodosius Port, it was built in the late 4th century during the reign of the Byzantine Emperor Theodosius I and become the city's most important commercial port.

Probably belonging to the ship's captain, the wooden object, whose cover is finely carved with decorations, is the size of a modern seven-inch tablet, but it's much thicker.

Paleontologists have just unearthed the fossilized bones of a gigantic dinosaur that's never been seen before. They believe it's an entirely new species - and based on the size of its bones, it's way bigger than what we thought was the biggest dinosaur ever. Meet the new number one among earthly creatures.

Based on the size of the thigh bone found at the dig site in Argentina, paleontologists estimate this dinosaur stood 130 feet long and 65 feet tall, and weighed in at a whopping 77 tons. That's seven tons heavier than what we used to think was the biggest dinosaur, Argentinosaurus. In other words, this jumbo-dino weighed as much as 14 African elephants, and with its neck held high the herbivore was seven stories tall. That's positively massive.