Ashoka ("Ashoka Chakra") from its base was placed onto the center of the National Flag of India. The capital contains four lions (Indian / Asiatic Lions), standing back to back, mounted on a short cylindrical abacus, with a frieze carrying sculptures in high relief of an elephant, a galloping horse, a bull, and a lion, separated by intervening spoked chariot-wheels over a bell-shaped lotus. Carved out of a single block of polished sandstone, the capital was believed to be crowned by a 'Wheel of Dharma' (Dharmachakra popularly known in India as the "Ashoka Chakra"). The Sarnath pillar bears one of the
Ashoka three colours, Saffron, White and Green with the Ashoka Chakra was selected. Ashoka is often credited with the beginning of stone architecture in India, possibly following the introduction of stone-building techniques by the Greeks after Alexander the Great. Before Ashoka's time, buildings were probably built in non-permanent material, such as wood, bamboo or thatch. Ashoka may have rebuilt his palace in Pataliputra by replacing wooden material by stone, and may also have used the help of foreign craftmen. Ashoka also innovated by using the permanent qualities of stone for his written edicts, as well as his pillars with Buddhist symbolism.