The islands, Borneo, Java, Sulawesi and Sumatra, are internationally recognised for their ecological diversity and rich culture.

According to Koesoemadinata, Professor Emeritus of Geology at the Bandung Institute of Technology (ITB), the name "Sunda" originates from the Sanskrit word "Cuddha," meaning white.

Reinout Willem van Bemmelen, another geologist, noted that during the Pleistocene era, there was a large volcano named Mount Sunda located north of Bandung in West Java.

Its eruption covered the surrounding area with white volcanic ash, giving rise to the name "Sunda."

The use of the term "Sunda" to refer to the Indonesian region dates back to the exploration report of the geographer Claudius Ptolemaeus in 150 AD.

This report served as a reference for the Portuguese when they arrived in Indonesia in 1500 AD and explored the Sunda kingdom in West Java.

Since then, the term "Sunda" has been widely adopted in earth sciences (geology-geography) as a reference for the Indonesian region, surpassing the usage of "Indonesia" in this field.

Spanning 473,481 square kilometres (182,812 sq mi),[2] Sumatra is home to human civilisations and tropical rainforests, which harbour a huge range of wildlife.

These regions were developed during World War II, to sustain functional political, economic and cultural relationships across the island.

[5] For instance, the Insular Riau region is situated along the central coast of Sumatra, and thus has a strong relationship with fishing, seafare and marine operations.

Each of these groups has unique traditions and ceremonies, which have been passed on through generations by oral, written, social and artistic communications.

[7] Ethnic groups are prominent in political climates[clarification needed] and are inherently linked to the religious profile of the island.

Gayo is a living language used by inhabitants of the central highlands of Aceh, which is located at the northern tip of Sumatra.

The forests have been subject to logging and deforestation for industrial developments, but most prominently palm oil and acacia plantations.

These natural disasters are due to Sulawesi's geographical location and close proximity to the equator and tectonic plates.

A large group populate the South of Sulawesi, which is characterised by valleys and plains which have nutrient dense soils that are ideal for agriculture and living off the land.

However, it can be assumed that the majority of Christians of the island are immigrants, as Islam has been ingrained into Sulawesi culture since its arrival in the 17th century.

Notable landmarks include Mount Mahawu, Tangkoko Batuangus Nature Reserve and Fort Rotterdam Makassar.

The niche habitat of Sulawesi means that the animals which inhabit the land are adapted to the specific environmental conditions, as well as to a unique diet.

Studies have shown that the two genera of primates that occupy Sulawesi, the Macaques and Tarsius, breed and thrive in specific areas across the island.

There has been a 12% loss of these breeding and contact zones as a result of land clearing, which has directly impacted the primates population.

There is concern that as the land continues to be cleared for agricultural purposes, many more species will be impacted and there will be a dramatic loss of overall biodiversity in Sulawesi.

The river basins lie in between the tropical rainforests and the coastline, acting as a pathway for trade and transport across the island.

[16] Key landmarks of Borneo include the Omar Ali Saifuddien Mosque in Brunei, Niah National Park in Sarawak, Bohey Dulang and the Kota Kinabalu in Sabah.

[19] Borneo has many natural wonders; the national parks are home to some of the world's most distinctive species of flora and fauna.

In recent years, palm oil plantations have drawn media attention, as the industry has had controversial effects on the native wildlife of Borneo.

The majority of the land has been cultivated for human usage; however there are still a range of forests and wild, uninhabited mountainous areas.

It was constructed in the 9th century and is decorated with numerous statues and intricate designs which tribute[clarification needed] the Buddhist religion.