Royal Observatory of Madrid

This guide to the Royal Observatory of Madrid opens in 1808, when Napoleon's occupying troops turned the barely-finished neoclassical dome into a gunpowder magazine. It traces how King Charles the Third and naval officer Jorge Juan first dreamed up the observatory, how architect Juan de Villanueva raised it on a hill by Retiro Park, and the prized telescope built in England by William Herschel that awaited inside. Look for the sixteen slender Ionic columns still ringing the lantern above the dome.