Chambord is the largest château in the Loire Valley, begun in 1519 as a hunting lodge for the young François I and continued under successive kings until it was completed around 1547. It is the supreme statement of the early French Renaissance: a symmetrical white-stone keep wrapped in a fantastical roofscape of turrets, dormers, a central lantern tower and 282 chimneys, set inside a walled park of 52.5 square kilometres — the largest enclosed park in Europe, ringed by a 31-kilometre wall.
At its heart is the open double-helix staircase — two spirals winding around a hollow core so that two people can climb without ever meeting — long associated with Leonardo da Vinci, who spent his last years nearby at Amboise under François I's patronage. Whether he drew it remains debated, but many scholars credit him with the design of the central stair. The château holds 440 rooms and 84 staircases, yet François I himself stayed barely seven weeks across his whole reign: Chambord was built to be seen and to host the hunt, not to be lived in.
The château and its park have belonged to the French state since 1930. Most of the original furniture was dispersed during the Revolution and the 19th century, so the visit is above all about architecture — the staircase, the vaulted halls, and the roof terraces where the court once watched the hunt return across the park. The ticket is open-dated: you choose your day, arrive during opening hours, and walk straight in.