Iron eggs (鐵蛋/铁蛋) are eggs which have been repeatedly stewed in a mix of spices and air dried. The resulting eggs are dark brown, chewy and, about half its initial size. The famous Tamsui Iron eggs store is Grandma’s Tiedan (阿婆鐵蛋) located at 135 Zhongzheng Road (Old Street)/新北市 淡水區 中正路135-1號.
For more information: http://en.wikipedia.org/wiki/Iron_eggs
 

Famous Iron Eggs for TWD100