4 Best Sights in Windsor, The Thames Valley

Signs warn drivers of "Boys Crossing" as you approach the splendid Tudor-style buildings of Eton College, the distinguished boarding school for boys ages 13–18 founded in 1440 by King Henry VI. It's all terrifically photogenic, with students still dressing in pinstripe trousers, swallowtail coats, and stiff collars. Rivaling St. George's at Windsor in terms of size, the Gothic Chapel contains superb 15th-century grisaille wall paintings juxtaposed with modern stained glass by John Piper. Beyond the cloisters are the school's playing fields where, according to the Duke of Wellington, the Battle of Waterloo was really won, since so many of his officers had learned discipline and strategy during their school days. Boris Johnson was the most recent of the country's many prime ministers to have been educated here. The Museum of Eton Life has displays on the school's history and vignettes of school life. From May through September, the school gives public tours (bookable online) on Friday at 2 and 4.

From William the Conqueror to Queen Victoria, the kings and queens of England added towers and wings to this brooding, imposing castle. Visible for miles—though the most impressive view is from the A332, coming into town from the south—it's the world's largest inhabited castle and the only residence in continuous use by the British Royal Family since the Middle Ages. Despite the many hands involved in its design, the palace manages to have a unity of style and character.

As you enter, Henry VIII's gateway leads uphill into the wide castle precincts, where you're free to wander. Across from the entrance is the exquisite St. George's Chapel (closed Sunday). Here lie 10 of the kings of England, including Henry VI, Charles I, and Henry VIII (Jane Seymour is the only one of his six wives buried here) along with one very famous queen; the chapel is the last resting place of Queen Elizabeth II and her husband Prince Phillip. One of England's noblest buildings, the chapel was built in the Perpendicular style popular in the 15th and 16th centuries, with elegant stained-glass windows, a vaulted ceiling, and intricately carved choir stalls. The colorful heraldic banners of the Knights of the Garter—the oldest British Order of Chivalry, founded by Edward III in 1348—hang in the choir. The ceremony in which the knights are installed as members of the order has been held here with much pageantry for more than five centuries. The elaborate Albert Memorial Chapel was created by Queen Victoria in memory of her husband.

The North Terrace provides especially good views across the Thames to Eton College, perhaps the most famous of Britain's exclusive public schools (confusingly, "public schools" in Britain are highly traditional, top-tier private schools). From the terrace, you enter the State Apartments, which are open to the public most days. On display to the left of the entrance to the State Apartments, Queen Mary's Dolls' House is a perfect miniature Georgian palace-within-a-palace, created in 1923. Electric lights glow, the doors all have tiny keys, and a miniature library holds Lilliputian-size books written especially for the young queen by famous authors of the 1920s. Five cars, including a Daimler and Rolls-Royce, stand at the ready. In the adjacent corridor are exquisite French couturier–designed costumes made for the two Jumeau dolls presented to the Princesses Elizabeth and Margaret by France in 1938.

Although a fire in 1992 gutted some of the State Apartments, hardly any works of art were lost. Phenomenal repair work brought to new life the Grand Reception Room, the Green and Crimson Drawing Rooms, and the State and Octagonal Dining Rooms. A green oak hammer-beam (a short horizontal beam that projects from the tops of walls for support) roof looms magnificently over the 600-year-old St. George's Hall, where the late Queen Elizabeth frequently hosted state banquets. The State Apartments contain priceless furniture, including a magnificent Louis XVI bed and Gobelin tapestries; carvings by Grinling Gibbons; and paintings by Canaletto, Rubens, van Dyck, Holbein, Dürer, and Bruegel. The tour's high points are the Throne Room and the Waterloo Chamber, where Sir Thomas Lawrence's portraits of Napoléon's victorious foes line the walls. You can also see arms and armor—look for Henry VIII's ample suit. A visit October to March also includes the Semi-State rooms, the private apartments of George IV, resplendent with gilded ceilings.

To see the castle come magnificently alive, check out the Changing the Guard ceremony, which takes place daily at 11 April to July and on alternate days at the same time August to March. Confirm the exact schedule before traveling to Windsor. Note that the State rooms (and sometimes the entire castle) are closed during official state occasions; dates of these closures are listed on the website, or you can call ahead to check. Admission includes an audio guide and, if you wish, a guided tour of the castle precincts. Entrance lines can be long in season, and you're likely to spend at least half a day here, so come early.

The remains of an ancient royal hunting forest, this park stretches for some 5,000 acres south of Windsor Castle. Much of it is open to the public and can be explored by car or on foot. Its chief attractions are clustered around the southeastern section, known (or at least marketed) as the Royal Landscape. These include Virginia Water, a 2-mile-long lake that forms the park's main geographical focal point. More than anything, however, the Royal Landscape is defined by its beautiful gardens. Valley Gardens, on the north shore of Virginia Water, is particularly vibrant in April and May, when the dazzling multicolor azaleas are in full bloom. If you're feeling fit, the romantic Long Walk is one of England's most photographed footpaths—the 3-mile-long route, designed by Charles II, starts in the Great Park and leads all the way to Windsor Castle.

Divided from the Great Park by the busy A308 highway, the smaller Windsor Home Park, on the eastern side of Windsor Castle, is the private property of the Royal Family. It contains Frogmore House, a lavish royal residence. Completed in 1684, Frogmore was bought by George III as a gift for his wife, Queen Charlotte. The sprawling white mansion later became a beloved retreat of Queen Victoria. It was also formerly home to the duke and duchess of Sussex, otherwise known as Prince Harry and Meghan Markle, and can still only be visited by guided tour on a handful of days throughout August; see  www.rct.uk for more information.

About 4 miles from Windsor Castle, the main horticultural delight of Windsor Great Park consists of 35 acres of ornamental gardens with impressive displays of 2,500 rosebushes and a tremendous diversity of trees and shrubs. The Savill Building, easily recognizable by its undulating roof in the shape of a leaf, holds a visitor center, restaurant, and terrace where you can dine overlooking the garden, as well as a large shopping area with plenty of gifts, cards, and original artwork.