Omashu delivery system

The Omashu Delivery System is a mail and package delivery system in the Earth Kingdom city of Omashu. The system consisted of a series of slides and chutes that the various packages went through to get to their destination. It was powered by Earthbending and gravity (Earthbending sent the packages up the slides, whilst gravity sent them down).

As seen in Return to Omashu and The King of Omashu, the slides are also rigged with a wide variety of loading docks, again power by earthbenders. This operation is clearly defined by a statement made by Aang: "Earthbending brings them up, gravity brings them down." It is unclear whther or not certain chutes slides into indivudual houses, though it's unlikely knowing the quantity of residents in Omashu. The goods transported here are varied, and not packaged in any sort of containers, as seen when Tom Tom and Momo land in a pile of Baccui Berries.

A younger Bumi and Aang used the system as what Bumi referred to as "The World's Greatest Super Slide", by putting themselves in a cart that was being sent down the slide. 100 years later, Aang took Katara and Sokka to Omashu, where he took them down one of the slides, though a slight accident on the chutes got them arrested. In Return to Omashu, Princess Azula was seen sliding on the chutes in her attempts to capture Aang, though neither was arrested this time.