Loha Prasat located in Wat Ratchanatdaram at the intersection between Ratchadamnoen Klang and Maha Chai Road, in Phra Nakhon district, Bangkok.
Meaning Temple of the Royal Niece, the temple was built to the order of King Nangklao (Rama III) for the princess granddaughter, Somanass Waddhanawathy in 1846.
Loha Prasat, which means iron castle or iron monastery (โลหะปราสาท), is composed of five towers, of which the outer, middle and the center towers contain large black iron spires. The 37 virtues that are required to reach enlightenment are signified by 37 golden spires. The 36-meter-high (118 ft) multi-tiered structure consists of 3 levels, the bottom one has 24 spires, the middle one 12 and the top level has 1 spire.