What is the setting in Jonathan Swift's Gulliver's Travels?

Swift's Travels into Several Remote
Nations of the World.  By Lemuel Gulliver (1726), aof eighteenth-century British
society and traveler's stories (which were very popular in England), has four settings, each
tied to one of Dr. Gulliver's four voyages.

When Gulliver's ship is wrecked
during his first voyage, he washes up on the beach in the land of Lilliput, where everyone
(except Gulliver) is about six inches tall.  Gulliver eventually becomes a nobleman of Lilliput,
initially helps the Lilliputians defeat the Blefuscans, their arch enemies, and then assists in
negotiating a peace treaty between the two countries.  While touring the island of Blefuscu,
Gulliver finds his wrecked boat, and with the help of the Blefuscans, refits the boat and is
eventually picked up by an English ship and returned to England.

On his
second voyage, Gulliver lands on the coat of Great Tartary, wanders away from the English
landing party, and is captured by the Brobdingnagians, who are about fifty or sixty feet tall.
 After being kept by a young girl as a curiosity, Gulliver ends up in the Brobdingnagian court
where the king becomes thoroughly disgusted by Gulliver's account of eighteenth-century British
politics and culture.  Gulliver eventually escapes from Brobdingnag but is marooned by Chinese
pirates on the island of Laputa.

Gulliver's third voyage (Laputa) allows
Swift to satirize the scientific community in Great Britain.  The Laputans, who are all
scientists, carry out experiments that have no practical value to the larger society: trying to
soften marble in order to make pillows; attempting to build houses and other buildings from the
top down; and training spiders to replace silkworms to create silk.  The Laputans spend so much
time thinking about science that they need servants to slap them with balloons to get their
attention on everyday life--eating, for example.

The fourth voyage to the
land of the Houyhnhnms, a country governed by intellectual horses and where humans are animals
known as "Yahoos," gives Swift the opportunity to criticize humanity.  Swift, in the
persona of Gulliver, argues, for example, that mankind should be, but is not, governed by reason
and that man allows the lowest part of his nature--lust and violent emotions--to govern his
nature.  Swift uses the Houyhnhnms to represent what mankind could be if mankind were ruled by
reason, and the Yahoos, who are violent and ungovernable, are unmistakeably men.  When Gulliver
returns to England, he is so alienated from men that he spends as much time as possible with
horses.

The four settings of Gulliver's voyages provide Swift with the
opportunity to discuss everything he feels is wrong with mankind in general and British society
specifically.