TopRq.com

A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos. Speleology is the science of exploration and study of all aspects of caves and the environment which surrounds the caves. Exploring a cave for recreation or science may be called caving, potholing, or, in Canada and the United States, spelunking...

Gold is a chemical element with the symbol Au (from Latin: aurum "gold", originally "shining dawn") and an atomic number of 79. It has been a highly sought-after precious metal for coinage, jewelry, and other arts since the beginning of recorded history. The native metal occurs as nuggets or grains in rocks, in veins and in alluvial deposits. Less commonly, it occurs in minerals as gold compounds, usually with tellurium...

A mirror is an object with at least one reflective surface. The most familiar type of mirror is the plane mirror, which has a flat surface. Curved mirrors are also used, to produce magnified or diminished images or focus light or simply distort the reflected image. Mirrors are commonly used for personal grooming or admiring oneself (in which case the old-fashioned term "looking-glass" can be used), decoration, and architecture...

Fortifications are military constructions and buildings designed for defence in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs. The term is derived from the Latin fortis ("strong") and facere ("to make"). Nomenclature Many military installations are known as forts, although they are not always fortified. Larger forts may class as fortresses; smaller ones formerly often bore the name of fortalices...

The Republic of Indonesia (Indonesian: Republik Indonesia) is a country in Southeast Asia and Oceania. Indonesia comprises 17,508 islands. With a population of around 230 million people, it is the world's fourth most populous country, and has the world's largest population of Muslims. Indonesia is a republic, with an elected legislature and president. The nation's capital city is Jakarta...

Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general. It ranges in scale from the subatomic to the cosmic. The word nature is derived from the Latin word natura, or "essential qualities, innate disposition", and in ancient times, literally meant "birth"...