Chak Chakoo is one of the traditional customs of the month of Moharram in the city of Estehbân in the Fârs region. Chak Chakoo is a type of traditional funeral lamentation that is celebrated in this city in the afternoon of Âshurâ in the presence of the inhabitants. The participants in the ritual first prepare two stones or two pieces of wood and in a row or at a distance of one step from each other, arrange themselves in an arc around the one who recites laments and turns. By reciting sad verses and following the instructions of the one who recites laments, the participants, instead of beating their breasts, hold the stones or two pieces of wood in two hands, raise them above their heads and beat them together; then in concomitance with the rhythm of elegy, they bend and again strike the two stones between the legs. Together they step forward and backward, and repeat the verse or the first verse of elegy. The number of participants increases gradually and the arc becomes bigger and bigger until it assumes the shape of a circle. Sometimes the circle from the center of the square widens, then a second circle forms as a spiral.