▁supported ▁by ▁the ▁alt ar ▁wall ▁and ▁two ▁freely ▁standing ▁pill ars ▁( a ▁more ▁advanced ▁design ▁that ▁appeared ▁after ▁the ▁ 1 1 th ▁century ). ▁Trans ition ▁from ▁the ▁pill ars ▁to ▁the ▁th ol ob ite ▁is ▁via ▁pointed ▁arch es . ▁In ▁addition , ▁the ▁pill ars ▁are ▁connected ▁to ▁the ▁northern ▁and ▁southern ▁walls ▁by ▁hel m - sh aped ▁arch es ▁( pro bably ▁ 1 6 th ▁century ). ▁The ▁yellow ▁t uff ▁from ▁which ▁the ▁c athedral ▁was ▁built ▁comes ▁from ▁Bol nis i , ▁a ▁town ▁south west ▁of ▁T bil isi . ▁The ▁fac ades ▁are ▁simple , ▁with ▁few ▁decor ations , ▁although ▁there ▁are ▁bas - rel ief ▁car v ings ▁of ▁a ▁cross ▁and ▁a ▁ch ained ▁l ion ▁on ▁the ▁western ▁side ▁and ▁an ▁ang el ▁and ▁sain ts ▁on ▁the ▁north . ▁All ▁six teen ▁windows ▁have ▁car ved ▁orn amental ▁frames . ▁Sh allow ▁car v ings ▁indicate ▁late ▁decor ation . ▁ ▁North ▁of ▁the ▁c athedral , ▁within ▁the ▁cour ty ard , ▁is ▁a ▁fre est and ing ▁three - story ▁bell ▁tower ▁d ating ▁from ▁the ▁ 1 4 2 5 ▁reconst ruction ▁by ▁King ▁Alexander ▁I . ▁L arg ely ▁destroyed ▁by ▁the ▁Pers ian ▁sh ah ▁Ag ha ▁Moh amm ad ▁Khan ▁Q aj ar ▁in ▁ 1 7 9 5 , ▁it ▁was ▁restored ▁to ▁its ▁present ▁condition ▁in ▁ 1 9 3 9 . ▁▁ ▁Ac ross ▁the ▁street