Found Short Stories, Volume 2

(Found in the Wikipedia entry for Albert Speer, the Nazi architect, imprisoned after the Nuremburg trials)

Later, Speer took to the prison garden for enjoyment and work. Heretofore the garden was divided up into small personal plots for each prisoner with the produce of the garden being used in the prison kitchen. When regulations began to slacken in this regard, Speer was allowed to build an ambitious garden, complete with a meandering path, rock garden, and a wide variety of flowers. The garden was even, humorously, centered around a "north-south axis", which was to be the core design element of Speer and Hitler's new Berlin. Speer then took up a "walking tour of the world" by ordering geography and travel books from the local library and walking laps in the prison garden visualizing his journey. Meticulously calculating every metre traveled, he began in northern Germany, went through the Balkans, Persia, India, and Siberia, then crossed the Bering Strait and continued southwards, finally ending his sentence in central Mexico.