Stop on this walk
Uranus
Smith Memorial Arch
At true scale: 3.1 in (7.8 cm) across
About this place
A mile and a half on from Saturn, and the walk has left the city grid for good. Richard Smith left $500,000 in his 1891 will for an arch honouring Pennsylvania's Civil War heroes; it was finished in 1912, fifteen years after work began. Uranus takes eighty-four years to go round the Sun once — it has managed a little over one orbit since the arch was topped out.