We were checking out the Jackson Homestead in Newton, Mass., and saw this towering Mansard mansion off in the distance, and had to extend our walk a bit.

This massive house began its life as the Potter Estate, but is known now as the Sisters of Saint Joseph Convent.

Built around 1860, the house contrasts with the symmetrical styling found in most Civil War-era houses in Newton Corner. Its carriage house, iron fencing and gardener’s cottage still remain.

John C. Potter Jr. was a shoe and leather industry entrepreneur who worked in Boston. He lived here until 1894, when banker Joseph Flanagan bought the manse. Flanagan added the Colonial revival wrap-around porch.

The expansive property at 71 Walnut Park landed on the National Register of Historic Places in 1986 for its architectural significance.