Short answers, pulled from the story.
The Spasskaya Tower was built by Italian architect Pietro Antonio Solari and completed in 1491. It was commissioned by Grand Prince Ivan III the Great, and the year 1491 is recorded in a Latin inscription still visible on the tower today.
The name Spasskaya comes from two sacred icons associated with the tower. The icon of Spas Nerukotvorny (Saviour Not Made by Hands) was placed above the gates on the inside wall in 1658, and the wall-painted icon of Spas Smolensky (Smolensk Saviour) was created on the outside wall in the 16th century.
The Spasskaya Tower stands 71 meters tall, measured with the red star that Joseph Stalin had placed on top in 1936 to replace the two-headed eagle from the tsarist period.
The Kremlin chimes, known in Russian as Kremlyovskiye kuranty, are the clock on the Spasskaya Tower that officially designates Moscow Time. The clock face has a diameter of 20 feet, and historical accounts trace the first clock on the tower to somewhere between 1491 and 1585.
The Spasskaya Gate was closed to all traffic in 1999. The decision followed problems in the 1990s when vehicle passage disrupted pedestrians heading to GUM and nearby shopping centers. The gate now opens only for presidential motorcades on inauguration day, Victory Day parades, and a few other designated occasions.
The icon of the Smolensk Saviour, painted on the outside wall of the tower in the 16th century, was plastered over by Soviet authorities in 1937. It was uncovered and restored in August 2010, and its reappearance revived the tradition of parade inspectors removing their headgear and crossing themselves before the gates during Moscow Victory Day parades.