The term 'Observatory Feature' can be summarized as a DOME, which is a four-letter word. A DOME is a curved structure that is typically used to cover a large area, such as a building or an observatory. It is usually made of a material such as concrete, steel, or glass and is designed to be strong and durable. Domes are often used in observatories because they provide protection from the elements while still allowing for a clear view of the night sky.