Ancient Structures found in Antarctica

While searching for anomalies in Antarctica, using Google Earth, I found several unnatural looking structures, including some that resemble possible remnants of ancient settlements.


Coordinates: 
Shadow Ancient Settlement: 78°42'19.86"S 86° 4'57.09"W 
Shadow Medieval Castle: 76°52'13.87"S 149°59'14.52"W 
Remnants Ancient Settlement: 64°26'3.64"S 57°59'44.89"W 
Structure old base: 76°40'34.55"S 125°52'55.89"W 
Top of Citadel: 75°45'25.91"S 128°11'59.44"W 
Underwater Structure: 66°59'6.63"S 142°44'44.82"E 
Walls and Walkway: 82°57'10.15"S 161°34'7.61"E 
Building Structures (3 objects): 76°39'29.74"S 125°49'15.36"W 
Building Structure:  69°47'50.62"S 159°33'41.53"E