The Tokugawa shoguns built this castle to remind Kyoto's imperial court who really ran things, and the imposing stone walls and ornate Ninomaru Palace still radiate that authority. Walk the 'nightingale floors' — engineered to chirp underfoot as a security alarm against ninja intruders — and marvel at rooms covered floor-to-ceiling in gold-leaf paintings of tigers and pines. The surrounding gardens shift through cherry blossoms, summer greenery, and autumn maples. The sheer scale of the place, dominating northwest Kyoto, makes the military ambition of the Tokugawa era viscerally tangible.