Seondeok (선덕여왕, 595-647) was the **27th ruler of Silla — the first reigning queen of any of Korea's Three Kingdoms**. She built Cheomseongdae, **the oldest surviving astronomical observatory in East Asia**, and oversaw the founding of the great Buddhist Hwangnyongsa Temple. **Famous for solving riddles and predicting the future** — including the time and place of her own death.
Subject of the popular Korean historical drama Queen Seondeok (2009).
Seondeok reduces to one — the number of first Silla queen.