The two elderly women in the cemetery's tiny visitor centre love their job. "This is the prettiest graveyard in the world," they say as I shelter from the rain.
"It's a perfect resting spot for poets, artists, musicians, writers." And anyone else really who happened to die in the Eternal City and not be Catholic.
I've just arrived at Cimitero Acattolico: a phrase which confirms the classic scene in A Fish Called Wanda suggesting anything spoken in Italian is instantly sexy. The "Protestant Cemetery" also includes the graves of Jews, other non-Christians, and a few agnostics.
Do the two have any favourite headstones?
"Yes, I like 'Any news today?'"says one. "He's no one famous, but it's what he said every morning to his friends. And they put it on his tombstone to keep that catchphrase going after he died."
Of course, like most visitors I'm here paying my respects to those giants of the Romantic age – John Keats and Percy Bysshe Shelley.
They died within a year of each other, and their remains (or most of them) are kept here, 20 metres away, in an English "Poet's corner" far removed from Westminster Abbey.
But the jolly women have something else to tell me. "If you're Australian, you'll want to see the grave of your famous poet, Bertram Ronald Whiting?"
There's an embarrassed pause as it becomes clear that I've never heard of Whiting – even when the women try to sell me the poetic volume that was published posthumously by his friends in 1991, three years after his death in Rome.
From them I learn writer and diarist Whiting joined the Australian Army in 1940, fought in Burma, served under Indian Viceroy Richard Casey, and volunteered (since he was a former middleweight boxing champion of the Australian Army) to be Mahatma Gandhi's bodyguard.
Where is Whiting's grave? The women search their database and come up with the following co-ordinates in a mixture of Italian and English: "Zona 3, Riquadro 2, Line 4, Tomb 13."
I set off with the map in the official guide book they have sold me (God, they're good!).
Bizarrely, Cimitero Acattolico is still dominated by Rome's only pyramid – the Cestius Pyramid, built in honour of a Roman tribune who lived in the 1st century BC.
Today Piramide is also a convenient stop on Rome's B Metro line from Rome's Terminus railway station – the next stop after the Colosseum and Circus Maximus.
The 2000-year-old pyramid serves as a gigantic tombstone to Keats and Shelley. Their actual graves are modest, and shared with friends.
When Keats arrived in Rome in 1820, it was a last resort. He had tuberculosis, and died – at 26 – a disillusioned man.
The words on his gravestone, written by his friend Joseph Severn, do not mention his name but are a tour de force: "This grave contains all that was mortal of a young English poet, who on his death bed, in the Bitterness of his Heart at the Malicious Power of his Enemies Desired these Words to be engraven on his Tomb Stone."
And the epitaph Keats wrote for himself? "Here lies one whose name was writ in water."
Fortunately, Severn is buried next to Keats and his tombstone proudly proclaims him to be the "devoted friend and death bed companion of John Keats".
By the time Keats died, Shelley was already tragically acquainted with this cemetery, along with his wife Mary, who wrote Frankenstein in 1818. Their son William died the following year and is buried here – somewhere.
Shelley's own burial is a gothic horror story in itself.
He drowned during a sailing trip aged 30, and his body was cremated in the presence of Byron and Trelawney (who now shares his grave). On Mary's orders, Shelley's heart was taken back to be buried in England.
But the cemetery guide book reveals the whole story.
When Shelley died, Mary was in Genoa. She asked "dear Severn" (buried next to Keats) to ensure the poet's ashes were placed alongside their baby.
Poor Severn disinterred the baby William only to discover "a skeleton five and a half feet tall (1.67 metres)".
Shelley's resting place is forever secured. William's has never been found.
But the women tell me it must be close by.
If you've been to Rome several times, or are there on a longer holiday and want a quiet, reflective and impossibly romantic place to spend an hour or two, add the Happy Cemetery to your list.
It is a beautiful garden – serene, fascinating and a perfect place to contemplate Rome's enduring magnetic attraction.
And if it rains? Just go and ask the women in the Happy Cemetery Visitor Centre a few questions.
Azamara Journey has a 12-night Mediterranean Jewels sailing departing from Barcelona to Venice on July 21, 2016. Ports include Civitavecchia (Rome). Fares start from $7179 a person, twin share for an interior stateroom. See www.azamaraclubcruises.com/en-au or phone 1800 754 500.
Steve Meacham travelled as a guest of Azamara Club Cruises.