By the end of this week the Thames Path will close between Tate Modern and Blackfriars Bridge and stay closed until New Year 2012.
The closure was delayed until the annual Thames Festival last weekend.
The riverside work is part of building a south bank entrance to Blackfriars Station which will now span the river on the existing railway bridge.
The diversion is being signed down Hopton Street, right into Southwark Street and right again into Blackfriars Road to reach Blackfriars Bridge.
There is also some extra signage pointing unhelpfully to non-existent toilets.
The Founders Arms pub is remaining open.
See page 34.