Sentinel Station is a Watchtower-class design that has been employed on the periphery of the United Federation of Planets since Starbase 47, known as Vanguard, was built in 2263.
The saucer section of the station contains a four-level terrarium. It is an open-air green-space containing natural turf parks and outdoor recreational.
At the center of the terrarium is a circular, four-storey tower enclosing turbolifts and conduits linking the administrative spaces above deck 9 to the living, operational, docking and engineering spaces below deck 14. The tower houses civilian-use offices and accommodations. Non-emergency medical facilities are located on Deck 14.
The outside edge of the terranium houses civilian-use offices, accommodations, institutional spaces (eg. schools) and entertainment venues. These spaces face both inward onto the open-air greenspace and outward with views of space.
Image courtesy of http://www.kanyon.com.tr/en/#!/home
One quarter of the outside edge is dedicated to the Promenade, four levels of shopping, dining and entertainment spaces.