The Nabatnaya (Alarm) Tower is an intermediate blind tower of the eastern side of the Kremlin, erected in the 1490s. Its simple quadrangular volume, finished with machicolations with a parapet, was built higher with a hipped four-sided top similar in detail to the Arsenal Tower in 1676-1686. The original forms of the construction are well preserved.

The main purpose of the tower is to house the bells of the Spassky alarm, the firefighting service of the Kremlin. In 1771 Catherine the Great ordered to tear the tongue of the alarm bell ringing during the "Plague Riot". The voiceless bell hung there for more than 30 years. It was dismantled during reconstruction works and placed in the Kremlin Arsenal at the beginning of the 19th century; it was transferred to the Armory in 1851.

The lower tier of the tower is a complicated multi-chamber room, connected with the passage part of the walls with stairs and apertures. It is separated from the second tier with a closed vault by a flat ceiling. The upper arched quadrangle turns into a hipped roof.

The height of the tower is 38 metres.

Nabatnaya Tower, main viewAlarm (Nabatnaya) TowerAlarm (Nabatnaya) and Tsar's (Tsarskaya) towers