Nouns denoting natural objects (not man-made)

Caribbean Sea
an arm of the Atlantic Ocean between North and South America; the origin of the Gulf stream
 
bathyal district
the steep descent of the seabed from the continental shelf to the abyssal zone
 
Tevere
a river of central Italy; flows through Rome to the Tyrrhenian Sea
 
Balkan Mountain Range
the major mountain range of Bulgaria and the Balkan Peninsula
 
Narragansett Bay
a deep inlet of the Atlantic Ocean in Rhode Island
 
Urubupunga Falls
a waterfall in the Parana river in Brazil
 
main
any very large body of (salt) water
 
Callisto
the second largest of Jupiter's satellites
 
Europa
the 4th largest of Jupiter's satellites; covered with a smooth shell of frozen water
 
nugget
a solid lump of a precious metal (especially gold) as found in the earth
 
antitauon
an antilepton of very great mass
 
neutrino
an elementary, electrically neutral particle with a very small mass
 
wetland
a low area where the land is saturated with water
 
expanse
a wide and open space or area as of surface or land or sky
 
floe
a flat mass of ice (smaller than an ice field) floating at sea
 
River Trent
a river in central England that flows generally northeastward to join with the Ouse River and form the Humber
 
deuteron
the nucleus of deuterium; consists of one proton and one neutron; used as a bombarding particle in accelerators
 
up quark
a stable quark with an electric charge of +2/3 and a mass 607 times that of an electron
 
point
a promontory extending out into a large body of water
 
Bering Sea
part of the North Pacific between Alaska and Siberia; connected to the Arctic Ocean by the Bering Strait
 
 List More