"It was a dangerous journey; any misstep could have cost him his life. In 1853 intrepid British explorer Sir Richard Francis Burton disguised himself as an Islamic pilgrim and made the trek into the heart of Arabia visiting the holy cities of Medina and Mecca. If his true identity as a European Christian had been exposed, the penalty for his indiscretion would have been death......
http://www.eyewitnesstohistory.com/mecca.htm
