The only sur­viv­ing bridge­head tow­er of the Krem­lin was built in 1516 by Ale­viz the Old at the same time as the bridge lead­ing to the Trin­i­ty Tow­er. He also built oth­er tow­ers and walls of the fortress on the Neglin­ka side. Until the 17th cen­tu­ry, the tow­er was sur­round­ed on all sides by water and served as a seri­ous obsta­cle to attack­ers. The tow­er was once cov­ered by a vault, but it was dis­man­tled in the 18th cen­tu­ry. The ori­gin of the name is not entire­ly clear and is asso­ci­at­ed with one of two words: kut — cor­ner, shel­ter and kutafya — a plump, clum­sy woman.