3

Famous Explorers

3

Isthmuses of the World

4

Maddy's Maryland Diary

3

Ibn Battuta

3

John Cabot

3

John Smith

3

Samuel de Champlain

3

David Livingstone

3

Daniel Boone

3

Neil Armstrong

3

Astronauts

3

Ferdinand Magellan

3

Francis Drake

3

Jacques Cousteau

4

Table Mountain, South Africa

3

Juan Ponce de León

3

Christopher Columbus

3

Vasco da Gama

3

Magnetism

4

Maddy's Iowa Diary

3

Amerigo Vespucci

3

Roald Amundsen

3

Sacagawea

3

Jacques Cartier

3

Marco Polo

3

James Cook

3

Leif Erikson

3

Zheng He

3

Edmund Hillary