But there are two places which we must glance at before we leave the City, whatever else we miss, and these are the Tower and St. Paul's Cathedral. And first of all we will go to the Tower, for it is the oldest and most famous of all the City's many buildings. Nay, the Tower is more than that: it is one of the famous buildings of the world. For many hundreds of years the grey old Tower has raised its walls beside the Thames, and in its time it has played many parts. It has been a fortress, a palace, a treasure-house, and a prison. William the Conqueror began it, William Rufus went on with the work, and the latter finished the central keep, the famous White Tower, the heart of the citadel. For many centuries the Tower was the strongest place in the land, with its thick walls and its deep moat filled with water from the Thames, and the rulers of England took great care to keep it in their own hands. To-day it is a show-place more than anything else, and everyone is free to visit it, to see the Crown jewels stored there, and to view the splendid collection of weapons and armour. But after all the place itself is the finest thing to see--to wander through the rooms where kings and queens have lived, to stand in the dungeons and prison-chambers where some of the best and noblest of our race have been shut up, and to climb the narrow winding stairs from floor to floor. Many of the prisoners of the Tower were brought into it by the Traitor's Gate, a great gloomy archway under which the waters of the Thames once flowed. In those days the river was the great highway of London, and when the judges at Westminster had condemned a prisoner to be sent to the Tower, he was carried down the river in a barge and landed at the Traitor's Gate. Many and many a poor prisoner saw his last glimpse of the outer world from the gloomy gate. Before him lay nothing save a dreadful death at the hands of the headsman. Outside the White Tower there is a garden, where once stood the block where the greatest of the prisoners were beheaded. Outside the Tower is Tower Hill, where those of a lesser rank suffered; we may still see in the Tower a headsman's block whereon heads have been laid and necks offered to the sharp, heavy axe. As for the names of those who have been executed in the Tower, history is full of them--Lady Jane Grey, Sir Thomas More, Anne Boleyn, Sir Walter Raleigh, Katherine Howard, the Earl of Essex, to name but a few who have suffered there. An earlier tragedy than any of these is the murder of the two little princes, Edward V. and his brother, put to death by command of Richard of Gloucester, Richard Crookback, their wicked uncle who wanted to seize the throne.