Tourists first noticed the spectacle as they waited in line to ride the elevators up to the viewing decks.
The Eiffel Tower has been temporarily closed after a man was seen climbing up its side on Monday.
The Eiffel Tower was evacuated of all visitors and then shut down today after a man was spotted climbing up the Paris landmark.
Visitors were advised to postpone their visit, while those already in the monument at the time the climber was spotted having to stay in on lockdown for a long time.
In October 2017, the tower also was evacuated after a man ventured out onto one of the beams and threatened to commit suicide.
The esplanade underneath "The Iron Lady", visited by some seven million people each year, also was evacuated.
Authorities wouldn't say how the trespasser managed to get past the Eiffel Tower's stringent security system.
A representative told Independent.ie that the man paid entrance to the Eiffel Tower and at the second level at 149metres began to climb.
The tower celebrated its 130th-anniversary last week.
The man, who has not yet been identified, clung to the Parisian landmark for more than six hours.
The first two floors can be reached by either elevator or stairs, but only elevators whisk people to the top observation deck.