The Royal Hospital Haslar operated for 256 years and was the last military hospital in the country when it shut down in 2009.
Since then it has undergone quite the transformation. It is now known as the Royal Haslar development and once the work is finished it will offer a mixture of open market and retirement apartments - as well as a care home, a boutique hotel and spa, healthcare hub, business space and retail premises.
Fox and Sons is selling a two-bedroom penthouse-style retirement apartment in Canada House at the site for £510,000.
It has 24/7 care support, emergency call and monitoring plus a resident manager.
There are lifts to all floors.
It is described as a fantastic seafront location and Royal Haslar is set in 62 acres of mature parkland and elegant, landscaped gardens.