Nature is endowed with unique geological features, significant in tracing the expression of earth’s history through ages. A rock is a solid mass of geological materials. Geological materials include individual mineral crystals, inorganic non-mineral solids like glass, pieces broken from other rocks, and even fossils. The geological materials in rocks may be inorganic, but they can also include organic materials such as the partially decomposed plant matter preserved in coal. A rock can be composed of only one type of geological material or mineral, but many are composed of several types. Figure 6.2 shows a rock made of three different kinds of minerals.
Rocks are grouped into three main categories based on how they form. Igneous rocks form when melted rock cools and solidifies. Sedimentary rocks form when fragments of other rocks are buried, compressed, and cemented together; or when minerals precipitate from solution, either directly or with the help of an organism. Metamorphic rocks form when heat and pressure alter a pre-existing rock. Although temperatures can be very high, metamorphism does not involve melting of the rock.
Here are seven prehistoric monuments in Kerala that will transport you to centuries past. These sites are also proof of how several cultures, which are now far flung from each other, had perhaps a few things in common, once upon a time.

Chowannur Burial Cave

The Chowannur Burial Cave, a prehistoric megalithic rock-cut cave located in Chowannur, Thrissur, has a single entry that takes visitors into a circular chamber, the only one in the cave. This site is a ‘centrally protected monument’ under the Archaeological Survey of India (ASI).

Kudakkallu Parambu

There are four umbrellas out of six that now remain intact, while the other two are partly broken A prehistoric megalithic burial site in Chermanangad, Thrissur, Kudakkallu Parambu features 69 megalithic structures spread over a small area. Its name is befitting as it translates to ‘umbrella-like stone field’. Different types of burials are observed here, and the ASI estimates the date of construction to be around 2000 BCE The largest Kudakkal measures 270cm (106.3 inches) high and 150cm (59 inches)

Edakkal Caves

Edakkal Caves also Edakal, are two natural caves at Edakkal, in Wayanad district of Kerala. The caves are situated 1,200 m (3,900 ft) above sea level on Ambukutty Mala, on the Mysore Plateau, in the Western Ghats.
The Edakkal caves are believed to be camping shelters of the Neolithic community (the south Indian Neolithic culture zone). The cave walls contain a collection of Neolithic rock engravings and images (which were incised over a period of time). The major part of images on the cave walls may belong to late Neolithic period (i. e., first millennium BC).With the exception of Edakkal, no concrete evidence for the existence of a true Neolithic culture in Kerala has so far been discovered.
The caves were discovered by Fred Fawcett, Superintendent of Police, Malabar District in 1896 who immediately recognised their anthropological and historical importance. He published an article (1901) about the caves in the Indian Antiquary (Volume 30), attracting the attention of scholars.
The caverns at Edakkal are not technically caves, but rather a cleft, rift or rock shelter approximately 96 ft (29 m) by 22 ft (6.7 m), a 30-foot-deep (9.1 m) fissure caused by a piece of rock splitting away from the main body. On one side of the cleft is a rock weighing several tons that covers the cleft to form the "roof" of the cave.

Eyyal Burial Cave

Eyyal Burial Cave is Another megalithic burial site in Thrissur lies in Eyyal. This site is a double chamber burial cave. Roman coins from the Republican period were unearthed here by the ASI. These coins date back to the first century AD.a region, and are dressed blocks of laterite arranged in a way that they resemble a snake’s hood.

Ariyannur Umbrella Stones

There are four umbrellas out of six that now remain intact, while the other two are partly in broken condition. Ariyannur is a megalithic burial site with a set of six umbrella-like stones, locally referred to as Kodakkallu (translating to Umbrella Stone). These are recognized as a centrally protected ancient monument by the ASI. Its location gives an impression that the stone structures were erected over an urn burial. There are four umbrellas out of six that now remain intact, while the other two are partly broken.

Kakkad Burial Cave

Kakkad Burial Cave near Kunnamkulam town in Thrissur has an entrance accessible by a flight of stairs. The cave is dome-shaped, and the ceiling has a circular opening. Other nearby megalithic burial caves include Kattakambal Burial Cave and Kandanassery Burial Cave. All of these are found within a 10-kilometre (6.2-mile) radius of each other.

The Phantom Rock

This rock is at height of 2600 feet183m above sea level. Phantom Rock is a beautiful archeological site located in Wayanad district, Kerala. Popularly known for its skull shaped rock, which is unique in its own way, it regularly draws a large influx of tourists and curious onlookers. This piece of natural art which has a skull shaped rock over a small boulder is formed out of huge metamorphic rocks and is locally known as “Cheengeri Mala” or “Thalappara”.
It is famous for the rock that is shaped in the form of a phantom skull and thus derives the name of this tourist attraction. This place is an exciting spot for trekkers and hikers offering some amazing opportunities for photography.
Locally known as Cheengeri Mala, this place offers a surreal respite from the crowds and noise. The landscape here is picturesque and surrounded by beautiful greenery that accentuates the brilliance of this archaeological wonder.
For the lovers of history, Phantom Rock is a wonderful getaway in Wayanad and attracts many tourists who are looking for offbeat things to do in Wayanad.