The princess will officially open Lancaster Community Fire and Ambulance Station in Cable Street on Wednesday May 29.
She also will visit Penny’s Hospital Almshouses in King Street to mark their tercentenary and Westfield War Memorial Village in West Road on its centenary.
At Penny’s Hospital the Princess will meet residents, wardens and trustees of Lancaster Charity, which runs the almshouses, founded in 1719 by William Penny, three times Mayor of Lancaster between 1694 and 1711.
These almshouses, which consist of 11 homes, warden’s accommodation and chapel, are Lancaster Charity’s oldest property, a Grade II* listed building currently being upgraded.
The charity has a total of 55 homes in Lancaster.
The Princess will go on to Westfield Village, where she will meet residents, veterans and trustees.
Westfield, which has 113 properties in a conservation area, was founded for the Armed Forces community after World War I by the Storey family and landscape architect Thomas Mawson.
Westfield House was the home of industrialist and philanthropist Sir Thomas Storey, Mayor of Lancaster four times between 1867 and 1886.
The family has been associated with the village throughout its existence.
Earlier, the Princess will be in Cable Street, where the former fire station was rebuilt and has been combined with the ambulance station, which was formerly in Langdale Road, Newton.
Princess Alexandra, 82 last Christmas Day, was Chancellor of Lancaster University from its foundation in 1964 until 2004 and was given the Honorary Freedom of Lancaster in 1987 on the golden jubilee of city status.