Construction of this elegant summer palace, an incredible art-nouveau creation, began in 1910 at the behest of Rama V (who died just after the project was started) and finished in 1916. It was designed by German architects who indulged the royal family's passion for all things European with a Poseidon statue, badminton court, ceramic cherubs lining the double spiral staircase and a state-of-the-art, for the time, adjustable shower in the king's bathroom.
The lack of furnishings and, usually, other visitors makes a visit feel quite odd. It's on a military base and normally no identification is required, but it's best to bring your passport in case things change.