Although the events leading up to the deaths have already been dissected in two lengthy investigations, the visit Monday and Tuesday marks the first time an inquest jury has left Britain.
There are concerns over swarming paparazzi similar to those who pursued the couple in their final moments. Where the 11-member jury will stay is top secret, and their exact itinerary while the court is "in session" in Paris will not be divulged in advance.
It is known, however, that they will visit the Place de l'Alma by the underpass where the Mercedes crashed and the Pitie Salpetiere Hospital where Diana died.
"It is very difficult to conduct this sort of visit where you are leaving the protection ... offered by your own legal system," said a spokesman for the inquest, who asked not to be named in keeping with British procedure. "All of a sudden, we are about to walk down streets in Paris with no legal authority over those people around us."
CBS News correspondent Sheila MacVicar reports French police and security services will keep the media away while the jury walks the full length of the tunnel where Diana and Dodi died. The identities of the six women and five men must be kept secret.
Under British law, inquests are held when someone dies unexpectedly, violently or of unknown causes.
Diana, 36, and Fayed, 42, were killed along with their driver, Henri Paul, when their Mercedes crashed in the Pont d'Alma tunnel shortly after midnight on Aug. 31, 1997. Bodyguard Trevor Rees was badly injured but survived.
The group was heading from the Ritz Hotel to Fayed's private Paris home near the Arc de Triomphe. Dodi Fayed's father, Egyptian-born billionaire Mohamed al Fayed, has said it was their engagement night.
Whether Diana and Fayed planned to announce their engagement the next day - and whether she was pregnant with Fayed's child - are questions the jury must try to clear up.
Mohamed al Fayed claims the couple was murdered in a plot directed by Prince Philip, Queen Elizabeth II's husband, to keep a Muslim out of the royal spheres.
The inquest, headed by Lord Justice Scott Baker, is to determine when, where and how they were killed. It opened last Tuesday and was expected to last no more than six months.
A French investigation concluded that the car was traveling at an excessive speed and the driver had a blood alcohol level more than three times the legal limit. Tests showed the presence of two prescription drugs, including the antidepressant Prozac, in his system.
A British investigation left it to the coroner's inquest to assign blame. Neither the French nor British investigations have blamed paparazzi pursuing the speeding car for the crash.
Some British press reports, however, have seized on footage showing the driver waving in the direction of photographer Jacques Langevin, who was at the back of the hotel with several colleagues. The reports have concluded that Paul may have tipped off photographers about the couple's plan to leave the hotel from its service entrance.
The wave, captured on one of the hotel's 43 security cameras, was among dozens shown to the jury in London.
In a bid to help the couple escape the cameras, Paul, also deputy head of Ritz security, had been called back to duty to drive the Mercedes that would pick the couple up shortly after midnight.
He was seen five times at the hotel's front entrance, where most photographers were gathered, and went out the back entrance three times before the couple was whisked into the car.
Langevin, the photographer, said he did not know Paul and denied there was any elaborate ruse.
"It's strange. There were 10 years in which judges could have asked the question" about the wave, he said. "There was no connivance."
Langevin said he had been at the back of the hotel because of professional experience. A colleague was posted at the front entrance.
"Henri Paul could have taken them out by the garage .... It's a lottery," he said.
Lord Justice Baker released a batch of photographs, including two unpublished photos taken by Langevin that may have been the last to capture the princess before the crash. One photo, taken as the car left the Ritz, shows only Diana's hair as she turns to peer out the back window.
Langevin called the release of the photos a betrayal of trust and reversed his decision to testify by video link at the end of the month, reports MacVicar. He said he cannot be compelled to testify at the inquest.
Langevin said that after years of court action, the release of the photos could pose new problems in France.
He was acquitted of invasion of privacy for the two photos. However, he and two other photographers were convicted and fined a symbolic euro for photos of the smashed car in the tunnel.
"It's a tragedy on a planetary scale since she was known the world over," said Langevin. But he added that he had covered gruesome conflicts around the globe and "perhaps we should keep some perspective, and our feet on the ground."
Jurors have also seen footage of the jeweler where Fayed bought a ring. Mohamed al Fayed and jeweler Alberto Repossi say it was an engagement ring.
Repossi told Italian daily La Stampa that he was "perhaps the only witness to the fact that Dodi and Princess Diana had it in mind to get engaged." He said she picked out the ring herself at his Monaco store that August - a star of five diamonds.
Scotland Yard interrogated him and his wife "as if we were two criminals," he said in the paper's Saturday edition.