This is far from an original puzzle, but I thought it fit our current fortnightly challenge so well that it ought to be included here.
I saw it on the Futility Closet website, but it was originally created in 1830 by London printer Charles Ingrey.
-- click the image for a more-detailed copy, or check out the zoomable version at the British Library --
The puzzle states:
Mending our Ways, our ways doth oft-times mar,
So thinks the Traveller by Horse or Car,
But he who scans with calm and patient skill
This "Labyrinthine Chart of London", will
One Track discover, open and unbarred,
That leads at length to famed St. Paul's Church Yard.
Suggested by the Stoppages occasioned by repairing the Streets. The object is to find a way from the Strand to St. Paul's, without crossing any of the Bars in the Streets supposed to be under repair.