# Intro to Multi-Block Structures Allura provides (as of writing) a few custom multi-block structures that have various purposes. A multi-block structure is defined as a small structure made up of multiple blocks in a particular pattern.

From left to right, Void Altar, Keystone Portal, Pylon

Each multi-block structure has a **trigger/interact** block that is used to **create and interact** with the structure. For the Pylon, this is the bell. For the Keystone portal, this is the lower gold block. For the Void Altar, this is the white candle. These structures can be built and used by any player, provided you build the structure exactly as shown. ### Ownership Multi-block structures are able to be owned by players. The player who creates the structure by interacting with the structure's **trigger/interact** block is made the owner of the structure. By owning a structure, **other players cannot break or rename your structure**. They can however use it. In structures that display a menu when interacting with them, there exists a 'locked' option at the top right of the menu. Clicking this allows you to toggle the structure between **locked** and **unlocked.**

A structure can only be locked and unlocked by the owner of it. When unlocked, any player can destroy the structure and/or rename it.