boot dangling from a milkwood tree near a spring where sailors often drew water, Aguada de São Brás (Mossel Bay). Miraculously, the message was retrieved by its intended recipient, João da Nova, admiral of the outgoing 3rd armada, the very next year. The tree became a de facto post office box, where sailors would exchange letters protected in boots, iron pots, or beneath rocks. Seamen would leave their messages behind, trusting that their countrymen would pick them up and deliver them to their correct destination, albeit very slowly. The Post Office Tree, now believed to be approximately 600 years old, still continues to send and receive mail. A large post office box shaped like a giant boot has been constructed beneath the tree, where people can send letters anywhere in the world and receive a special stamp. Presumably, delivery now takes less than a year. Types of post boxes Varieties of post boxes (for outgoing mail) include: Lamp box Pillar box Wall box Ludlow style wall box Some postal operators have different types of post boxes for different types of mail, such as, ordinary post, air mail and express mail, for local addresses (defined by a range of postal codes) and out-of-town addresses, or for post bearing postage stamps and post bearing a postage meter indicator. Some countries have different coloured post boxes; in countries such as Australia, Portugal, and Russia, the colour indicates which type of mail a box is to be used for, such as 1st and 2nd class post. However, in Germany and parts of Sweden, because of postal deregulation, the different colours are for the different postal services. Other nations use a particular colour to indicate common political or historical ties. Post boxes or mailboxes located outdoors are designed to keep mail secure and protected from weather. Some boxes have a rounded or slanted top or a down turned entry slot to protect mail from rain or snow. Locks are fitted for security, so mail can be retrieved only by official postal employees, and the box will ordinarily be constructed so as to resist damage from vandalism, forcible entry, or other causes. Bright colours are often used to increase visibility and prevent accidents and injuries. Entry openings are designed to allow the free deposit of mail, yet prevent retrieval via the access slot by unauthorised persons. Clearance Post boxes are emptied ("cleared") at times usually listed