This golden, bell-shaped stupa on the upper terrace of Wat Phra Kaew is the tallest structure in the Grand Palace complex and can easily be seen from the Chao Phraya River. This reliquary called Phra Siratana Chedi was built during the 19th century in a Sri Lankan style. It is said to contain a relic, perhaps a bone or hair, from Gautama Buddha who died around 400 B.C.