Rubuta ci gaba don wannan sakin layi - Wannan nau'in kewaye, wanda Helenawa suka kira ἀποτειχισμός da περιτειχισμός, Peloponnesians sun yi amfani da shi a cikin kewaye da Plataea (Thucyd. ii.78, iii.20-23). Layin su sun ƙunshi bango biyu (a bayyane yake na turf) a nesa na ƙafa 16, wanda ya kewaye birnin a cikin wani da'irar. Tsakanin ganuwar akwai bukkoki na masu kewaye. Ganuwar tana da battlements (ἐπάλξεις), kuma a kowane battlements goma akwai hasumiya, ta cika ta da zurfinta duka sararin da ke tsakanin ganuwar. Akwai hanyar wucewa ga masu kewayewa ta tsakiyar kowane hasumiya. A waje na kowane bango akwai rami (τάφρος). Wannan bayanin zai kusan amsa daidai ga yanayin Roman na kewaye, wanda wasu daga cikin mafi kyawun misalai sune na Carthage a cikin zamani Tunisia ta Scipio (Appian, Punic. 119, & c.), na Numantia a cikin Spain ta zamani ta Scipio (Appian, Hispan. 90), da kuma na Alesia
a cikin Faransa ta zamani ta hanyar Kaisar (Bell. Gall. vii. 72, 73). Hasumiyoyin da ke cikin irin wannan layi sun kasance kamar waɗanda aka yi amfani da su wajen kai hari ga wuraren da aka ƙarfafa, amma ba haka ba ne, kuma ba za a iya motsawa ba. (Lipsius, de Milit. Rom. v.5, a cikin Oper. iii. pp156, 157; Poliorc. ii.1, a cikin Oper. iii.283).