Space

Space
      is the boundless three-dimensional extent in which objects and events have relative position and direction.^[1] Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, withtime, to be part of a boundless four-dimensional continuum known as spacetime. read more

Deserts

Deserts

Far from being barren wastelands, deserts are biologically rich habitats with a 

vast array of animals and plants that have adapted to the harsh conditions 

there. Some deserts are among the planet's last remaining areas of total 

wilderness. Yet more than one billion people, one-sixth of the Earth's population, 

actually live in desert regions. read more

Cave

Cave

A cave or cavern is a hollow place in the ground, especially a natural 

underground space large enough for a human to enter. 

Caves form naturally by theweathering of rock and often extend deep

 underground. The word cave can also refer to much smaller 

openings such as sea caves, rock shelters,

and grottos. read more