Built as part of the redevelopment of Chatham town centre in the 1970s, the Pentagon also features the high rise Mountbatten House office block, which has controversially stood empty or part-used for most of its history.

the Pentagon, Mountbatten House and the Brook multi-storey carpark are built in a distinctive orange-red brick with grey concrete, which resembled the "brutalist architecture" trend at the time.

As of October 2024, big and small businesses located in the Pentagon include: The long-established WHSmith store closed on 15 April 2015 following expiry of their unit's lease.

There were also two adult evening venues – The Blue Grotto Wine Bar (in the late 70's)[3] (situated by the public toilets, taxi rank and exit to Mountbatten House) which is now a dry cleaners, and Scamps (later Van Damme) Night Club, which is now the bowling alley.

The fountain and seating were removed, along with an old-style escalator to the side of Sainsbury's, a staircase by C&A (now Wilkinsons) and a sloped walkway for wheelchair access to the upper level.

In their place, modern glass lifts and escalators were installed, along with new ceilings and lighting, giving the centre a much brighter atmosphere.

Owing to the various alterations going ahead in Chatham town centre and to the new bus interchange facility in Globe Lane, the Pentagon is planned to be re-developed as well.