The meticulously restored exterior of this late-19th-century mansard-roofed Victorian home in Cambridge, Mass., gives no clue to the presence of a beautifully crafted and surprisingly whimsical central staircase within. Built and installed by Jed Dixon's North Road Stairbuilders of Foster, R.I., the winding stair's sinuous mahogany handrail continues unbroken from the finished basement level to the third-floor gallery landing.

Railing parts like these don't come in a box: The starting newel post was hand-carved by North Road's Michael Kennedy and modeled after a National Geographic photo of a tropical strangler fig tree with raveling, cascading roots. Even the beading on the rail begins as a slender root tendril that travels up the newel's trunk. Carving and installing the handrail required about 800 man-hours; the entire stair project took nearly 3,000 hours.