Why is the Verne prison on portland built underground?

Is the Great Barrier Reef an atoll? Why is the canopy layer most important in a rainforest? What is a non tropical country? Why is the Washington Monument famous? What shops can you pay the dartford crossing? How long is the Niagara River? What animals are in the Sahara Desert? Who is the patron saint of tourists? When did the great belin wall come down? What twice daily event would cause wells and water levels around Jamestown to rise Causwells and freshwater streams to become brackish? What does the Suez Canal connect? Why was the mission at La Bahia built? Who is the Frenchman who explored the lower Mississippi River Valley? What are five countries in Africa that have coastlines on the Atlantic Ocean that lie on or between 20 degrees north an 10 degrees north? Did elisha or Elijah part the Jordan river? What is the process called when algae absorb water? How does the buck-ham birding survive in deserts? What is stream B in relation to the river into which it flows? What is the largest lake in Guam? How do the rocks of the Grand Canyon indicate marine transgressions or regressions?

Why is the Verne prison on portland built underground?