The Chamber of Time is a secret feature of Geometry Dash, being introduced in Update 2.1. It is located through a door by the 'ground' in the centre of the Coming Soon screen of the main level slider, but is hidden until the orange lock in the Basement has been selected, followed by the door's hidden location being physically discovered. After doing so, the door will remain locked until the Master Emblem has been purchased from the secret shop, after which the Chamber of Time can be accessed.
The Chamber of Time contains a text field and a feline ring-handle button below it, referred to as the Gatekeeper. Pressing the button will return a response based on what has been entered into the text field. By entering specific phrases, Icon Kit rewards and associated achievements can be unlocked. Initially, there is a chest in the lower right corner which contains an orange key for the orange lock in the Basement.