Removing zones from a new map of the London Underground network has made it "confusing", a passenger watchdog said.
Transport for London (TfL) distributed the map last weekend without the River Thames and the fare zones marked on it.
London TravelWatch said the map had needed refining but the decision to omit the river and zones was "foolish".
But TfL said the previous map had become "cluttered" and lost its "simplicity". The revised map was based on feedback from passengers, it said.
A spokesperson for TfL said: "As the transport network has expanded over the years, the map has become increasingly cluttered and has lost the simplicity which made it so effective.
"Customer feedback, particularly from those less familiar with London, has been that this has made the map progressively more difficult to use.
"While the latest version does not show the indicative path of the Thames, it continues to include all of the interchanges that are available to transfer from the Tube and other services to river transport services."
But a spokesperson for London TravelWatch said while the decision to refine the map was sensible further revision was needed.
She said: "We would question the removal of the river which was a geographical landmark. We think the removal of the fare zones is foolish.
"If they (tourists) see maps without zones, people will not know there are zones, so it is potentially confusing," she said.
A spokesman for Visit London said: "Most visitors' journeys tend to be about individual sights and attractions so it may not matter too much whether it's immediately obvious if they're north or south of the river.
"But if they (tourists) don't know the pricing structure from the map, how else will TfL make it easy for visitors to understand what kind of ticket they should be buying?"
TfL said the river and the zones were not originally part of the map but were added as the network expanded.
The network's maps are usually updated twice a year to incorporate upgrades and extensions.