Keldor's streets don't join up
Castle Street, Bridge Street and Dock Street are each walled into separate stretches. Walking along a street never gets Dizzy where he wants to go.
Nudge 1Where to look
The way between the stretches is underground: every tunnel door (B at the arch) leads to a different stretch of another street.
Nudge 2A stronger push
The signposts in the tunnels show the streets as a map. Learn the pairs: they never change.
Show the solutionThe whole answer, with a video
The tunnels join: Castle Street east and Bridge Street east; Castle Street east and Dock Street east; the middle of Castle Street and Dock Street west; Castle Street west and Bridge Street west (two tunnels); Castle Street west and Dock Street west; Bridge Street east and Dock Street west. Bridge Street's far west (high up, at the top of its slope) leads on to the graveyard. Crystal Falls joins Castle Street's east end.
Why it works
The streets are long areas with solid walls across them (Castle Street has two), so each wall turns one street into two or three places, and only the tunnels connect them.