They have been found in most parts of the subcontinent except the far south. Some types have a fairy-wide distribution, while others (such as those found at Ayodhya and Kaushambi, which seem to have been issued in the last 3rd or early 2nd century BCE) have a more restricted range of circulation. Kaushambi, uninscribed, cast copper unit Tree in railing in centre, wheel above Nandipada to left, swastika above Ujjaini symbol to right, and six-peaked hill at bottom Rev: Lanki bull walking to left, four nandipadas above in front of a triangular-headed standard. Bopearachchi & Pieper These coins were made by melting metal and pouring it into clay or metal moulds.