Is it thorny prison bars or the South African leader's profile? Depends on where you stand.
To commemorate the 50th anniversary of the arrest of Nelson Mandela, South Africa unveiled this monument last month on a highway near Howick, some 60 miles south of Durban. It marks the site where Mandela, traveling under the pseudonym David Motsamayi, was stopped and arrested in August 1962. He spent the next 27 years in prison before being released in 1990, and became South Africa's first democratically elected president four years later.
Designed by Marco Cianfanelli, the sculpture is composed of 50 steel rods rising over 30 feet into the air from a cement base. To a passersby, it resembles an array of thorny prison bars, before showing, at the proper angle, the contours of Mandela's face, and then sliding back into abstraction. It's not urban, but it's a great example of public art that uses perspective and place to its advantage.
All images, except where noted: Jonathan Burton.