Site 16: St. Angelo's - Guard Tower

This site was actually on top of a grotto. The grotto was built in 1530 using the wall of one of the towers of the original fortress. The first Grand Master (head of the Knights) ordered the construction of this grotto as a place that would provide shade all day--every day of the year--so that the Knights would always have a place to cool off during the hot summers. When the tower portion became obsolete due to the new fortifications, it was turned into water storage. The roof of the grotto and adjacent building were designed with trenches so that rain water would fill the cistern. The access point was a trapdoor on the roof of the grotto. The water in this cistern was much clearer than the the first site, so the video clarity was much higher. The cistern contained quite a bit of water in the relatively small area with about 7 feet deep. A short video of what the robot saw during the 2009 expedition can be found here.

Shown below is the sonar data image map.