The Eiffel Tower was closed and surrounding streets put on lockdown after a man was spotted scaling the upper part of the 1,000ft high landmark.
Police and emergency workers were scrambled to the monument in Paris on Monday due to the climber.
A spokesman for the tower said the individual had tried to climb up the tourist attraction.
Dramatic images showed a person dangling just below the third and highest level of the structure, which stands at around 900 feet.
A rescuer dressed in red was pictured just above him.
Police said in a statement that the climber was a man.
It was not immediately clear how the trespasser managed to get past the tower's stringent security system.
A Paris police spokeswoman said a team of firefighters, including a climbing specialist, remain on the scene.
"The man entered the tower normally and started to climb once he was on the second floor," a spokeswoman for the tower's operator told Reuters.
The intruder's motivations remain unclear.
Officials have not immediately provided further information about the incident. It is not known when the Eiffel Tower will reopen.
It's not the first time a daredevil has attempted the feat.
In 2015, British "freerunner" James Kingston climbed the edifice without safety ropes and without permission, dodging security cameras as he went.
The tower, the tallest structure in Paris, is 324 meters (1,063 feet) high, about the same height as an 81-story building.
Additional reporting by the Associated Press.
