...two bastions, one in the northern corner of the square mounting five cannons on two floors, and another bastion in the southern corner mounting four cannons. Diary of Fr. Mariano Payeras, 1822. In the two corners opposite each other, one overlooking the mountains and the other overlooking the sea, are mounted 12 pieces of artillery up in two towers or lookout platforms. Each piece is of eight caliber and six are located in each tower.Report by Mariano G. Vallejo, 1833.

The two blockhouses were noticed by priest and soldier alike, but apparently no visitor observed that one is seven-sided (the northwest) and one eight-sided (the southeast). Both towers stood, quite decayed, for many years.

Twenty-seven days after Fort Ross officially became a historic site of the State of California, the massive earthquake of April 18, 1906 struck. Due to the fort’s proximity to the San Andreas fault, all of the historic buildings suffered structural damage. The Russian blockhouses and the chapel, which had successfully withstood the wind and rain for nearly a century, were now in a state of collapse. The southeast blockhouse was not renovated until 1930. Original floor boards from the officials’ quarters were set in this eight-sided blockhouse floor; they are still in place. In 1948, ruins of the northwest blockhouse were removed, and it was reconstructed in 1950-51 using Russian joinery techniques. In 1956-57, the southeast blockhouse was again repaired.