Stonehenge is a prehistoric megalithic structure on Salisbury Plain in Wiltshire, England, two miles (3 km) west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around 13 feet (4.0 m) high, seven feet (2.1 m) wide, and weighing around 25 tons, topped by connecting horizontal lintel stones, held in place with mortise and tenon joints, a feature unique among contemporary monuments.[2][3] Inside is a ring of smaller bluestones. Inside these are free-standing trilithons, two bulkier vertical sarsens joined by one lintel. The whole monument, now ruinous, is aligned towards the sunrise on the summer solstice and sunset on the winter solstice. The stones are set within earthworks in the middle of the densest complex of Neolithic and Bronze Age monuments in England, including several hundred tumuli (burial mounds).[

Windsor Castle is a royal residence at Windsor in the English county of Berkshire, about 25 miles (40 km) west of central London. It is strongly associated with the English and succeeding British royal family, and embodies almost a millennium of architectural history. The original castle was built in the 11th century, after the Norman invasion of England by William the Conqueror. Since the time of Henry I (who reigned 1100–1135), it has been used by the reigning monarch and is the longest-occupied palace in Europe. The castle's lavish early 19th-century state apartments were described by the art historian Hugh Roberts as "a superb and unrivalled sequence of rooms widely regarded as the finest and most complete expression of later Georgian taste".[1] Inside the castle walls is the 15th-century St George's Chapel, considered by the historian John Martin Robinson to be "one of the supreme achievements of English Perpendicular Gothic" design.