Mingun Pahtodawgyi (Mingun, Myanmar)
In 1790, when construction began on the huge structure shown in our January mystery photo, the plan was that it would eventually reach a height of 490 feet. However, the project was abandoned long before that. Today, the Mingun Pahtodawgyi -- a monument stupa in the town of Mingun, located across the Irrawaddy River from Mandalay in central Myanmar -- is "only" 164 feet tall and is sometimes referred to as the "world's largest pile of bricks."