Within the Inner Ward, by the side of the Wakefield Tower, stood, until the summer of 1899, an ugly building called the Main Guard, and it is in front of this building that the ceremony of receiving the Tower keys takes place nightly. Every evening just before midnight the Chief Warder and the Yeoman Porter meet together and proceed to the main guard-room. The Yeoman Porter carries in his hand his bunch of great keys, and on arriving at the guard-room he asks for “The escort of the keys.” This escort consists of a Beefeater (a sergeant) and six private soldiers. The sergeant carries a lantern, and the whole party then proceeds to the outer gate, where the soldiers assist the Yeoman Porter to close it. The latter then takes his keys and locks the gate, after which the procession is reformed for the return. As the party passes the sentinels on its way back, the latter challenges it with, “Who goes there?” The Yeoman Porter makes answer “The keys!” To this the sentry calls out “Advance King Edward’s Keys!” and the escort proceeds onward to the Main Guard. When this is reached the same ceremony is gone through, at the conclusion of which the officer of the guard and the escort salute the keys by presenting arms, after which the Yeoman Porter cries “God preserve King Edward!” The keys are then carried by the same guardian to the King’s House, or, as it is sometimes called, the Governor’s House, and placed for the night in the Constable’s office. Probably few know that, with the exception of the Sovereign and the Constable of the Tower, the password of the fortress is known only to the Lord Mayor of London, the word being sent to the Mansion House, quarterly, signed by the monarch. This is a survival of an ancient custom. [Illustration: _Groining in Ceiling of the Bloody Tower._] In early days a building, with towers attached, stood between the Main Guard and the White Tower, which is called in the old plans of the fortress “Cold or Cole Harbour.” When in 1899 the Main Guard was pulled down the old wall of Cold Harbour was laid bare, and at the same time a well with a stone lining to it, and a subterranean passage were discovered. The subterranean passage ran to the east of the Wakefield Tower and opened out towards the river front at the eastern side of St Thomas’s Tower, at a depth of five feet below the actual surface of the ground; it was six feet high, and so narrow that only one person could pass along it.