Later variations of the sole ard come in two types&colon; the triangular and quadrangular ards. These whistles have mouthpieces in quadrangular, rectangular, ellipsoidal and conical shapes. Their often quadrangular stems are unbranched or branched, erect, ascending or spreading. Rectangular shapes are very common (as in castra and quadrangular castles). The city is divided into a number of concentric quadrangular streets around the temple. The interior hall is screened with ionic columns supporting a quadrangular lantern dome. Two gates pierce each of the glacis of the quadrangular plan. Originally it enclosed a quadrangular courtyard. A quadrangular castle, Bodiam is roughly square-shaped. The anterior grey column, directed forward, is broad and of a rounded or quadrangular shape. Other geometries exist, like serpentine or quadrangular. The Abbey church occupied the centre of a quadrangular area, about square. The ruins of this quadrangular structure can still be found NW of the central square. The tomb of Bani Begam is in the centre of a large quadrangular garden. A new type of grave, quadrangular burial mounds, began to develop.