Chocolate Hills

There are many round hills in a place called Bohol.

These hills are shaped like little domes. They are made of hard rock from the sea.

Green grass grows on the hills. When it is dry, the grass turns brown. Then the hills look like chocolate!

There may be as many as 1,776 hills. They are a very special sight to see.

The Chocolate Hills are a special sight in Bohol.

They are many small, round hills. Some people count 1,260 hills. Others think there are up to 1,776 hills. These hills are shaped like domes. They are also shaped like cones.

Most of the hills are covered in green grass. During the dry season, the grass dries up. It turns a chocolate-brown color. This is how the hills got their name!

These hills are made of marine limestone. Limestone is a type of rock formed in the sea. Long ago, these rocks were under the ocean. They contain fossils of coral and shells.

The hills grew when the rocks moved above sea level. Rain and water then wore the rocks down. This shaped them into the hills we see today.

The hills are a national monument. This means the government works to protect them. People visit from all over to see them. Some hills are in towns like Carmen and Sagbayan.

The Chocolate Hills are a famous sight in the Philippine province of Bohol.

These hills are very special because of their unique shape. They look like small mounds or haycocks. Most of them are shaped like cones or domes. There are at least 1,260 hills in this area. Some people believe there are as many as 1,776 hills. They cover a very large space. These hills are so important that they are on the provincial flag.

These hills get their name from a change in color. Most of the time, the hills are covered in green grass. This grass includes types like *Imperata cylindrica*. However, the color changes during the dry season. The grass dries up and turns a chocolate-brown color. This makes the hills look like giant chocolate drops.

In the spaces between the hills, people grow rice. Other crops are also grown on the flat lands. This change in color is a wonderful thing to see. It happens because of the weather and the plants.

Scientists have figured out how these hills were made. They are called conical karst. This means they are shaped by water. Long ago, these hills were under the ocean. They are made of marine limestone. This rock contains fossils of coral, shells, and algae.

Over a long time, the rocks were pushed up above the sea. This happened because of tectonic processes. Once the rocks were above water, rain and streams began to wear them down. This erosion shaped the limestone into the hills we see today.

Many people visit these hills to see their beauty. The main place to view them is the Chocolate Hills Complex in Carmen. You can also see them from Sagbayan Peak.

The hills are a very important treasure for the country. The government named them a National Geological Monument in 1988. Later, in 2018, they became a national park. The government wants to protect them from being destroyed. Some people have even suggested putting them on the UNESCO World Heritage List. This would help the whole world know about them.

Even though they are protected, the hills face some hard jobs. Sometimes, people use quarrying to get rocks for building. This can threaten the natural plants on the hills. In 2013, a large earthquake hit the island of Bohol. The earthquake was near Sagbayan. It was so strong that it destroyed a viewing deck. One of the hills even gave way a little bit. In 2024, a grass fire also burned two hills in Carmen. These events show why it is so important to take care of the hills.

The Chocolate Hills are a unique geological formation located in the Philippine province of Bohol. These hills consist of a massive collection of mounds that create a rolling, uneven landscape. Scientists estimate there are at least 1,260 individual hills, though some counts suggest there may be as many as 1,776. They spread across an area of more than 50 square kilometers. Because of their striking appearance, they are featured on the provincial flag and seal of Bohol.

These hills are famous for a dramatic change in color that happens every year. Most of the time, the mounds are covered in lush green vegetation. The plant life is dominated by grass species like *Imperata cylindrica* and *Saccharum spontaneum*. However, during the dry season, this grass dries up. The vegetation turns a deep chocolate-brown color, which gives the hills their name. In the flatlands located between the hills, farmers cultivate rice and other cash crops.

The hills are actually made of limestone, a type of rock formed from ancient sea life. Specifically, they are composed of Late Pliocene to Early Pleistocene marine limestone. This rock is thin to medium-bedded and can be sandy or rubbly. Because it formed in the ocean, the limestone contains many fossils. You can find remains of coral, mollusks, algae, and shallow marine foraminifera within the stone.

Geologists call these formations conical karst. This term describes a landscape shaped by the way water interacts with certain rocks. The process began when these limestone layers were uplifted above sea level. This movement was caused by tectonic processes, which are shifts in the Earth's crust. Once the rock was above the water, it was fractured. Then, a combination of rainfall, surface water, and groundwater began to dissolve the limestone. This chemical dissolution, along with erosion from streams, carved the rock into the symmetrical, dome-shaped mounds we see today.

While many people have suggested different origins, science has ruled out several popular theories. Some people once believed the hills were created by sub-oceanic volcanism or volcanic eruptions. However, geologists have found no exposed or associated volcanic rocks in the area. Other theories suggested that tidal movements or massive geological shifts created the mounds. Scientists note that these ideas lack the corroborating evidence needed to prove they are true. The karst dissolution process remains the most accurate scientific explanation.

The Chocolate Hills are highly significant to the Philippines and are protected by law. The National Committee on Geological Sciences declared them a National Geological Monument on June 18, 1988. In 1997, President Fidel V. Ramos signed Proclamation No. 1037 to further protect the area. In July 2018, the hills were officially declared a national park under the Expanded National Integrated Protected Areas System Act. The government also submitted the site to UNESCO to be considered for the World Heritage List.

Despite these protections, the hills face several modern challenges. One major concern is the conflict between tourism, mining, and land use. Some hills were originally classified as private land, which led to social unrest and conflicts with groups like the New People's Army. Additionally, quarrying activities for construction materials can threaten the natural vegetation. The hills have also faced natural disasters. In 2013, a magnitude 7.2 earthquake struck near Sagbayan, causing one hill to give way and destroying a viewing deck. More recently, in April 2024, a grass fire burned two hills in Carmen.