Explore the real-world places that appear in When in Rome by Ngaio Marsh. Each location on the map shows what happens there in the novel, the real history of the place, and what's there today. Featured locations include Roman Forum, The Colosseum, Trevi Fountain, St. Peter's Basilica, Spanish Steps and 6 more.
Via della Salara Vecchia — Ancient heart of Rome
Inspector Alleyn and his tour group explore the ancient ruins where Roman senators once debated. The group's guide provides commentary on the historical significance while Alleyn observes the dynamics between tour members. The vast archaeological site serves as a backdrop for the growing tension that will soon explode into murder.
The Roman Forum was the center of political, commercial, and religious life in ancient Rome for over a millennium. It housed the Senate, law courts, and temples, serving as the beating heart of the Roman Empire until its decline in the 8th century.
Now one of Rome's most visited archaeological sites, the Forum welcomes millions of tourists annually. Visitors can walk the same paths as Caesar and Cicero, with extensive ruins and informative displays bringing ancient Rome to life.
Visit: Roman Forum Archaeological Site (historic site)
Piazza del Colosseo — Rome's iconic amphitheater
The tour group visits Rome's most famous landmark, where Alleyn notes the guide's unusual behavior and the strange dynamics among the tourists. One tourist makes cryptic comments about gladiatorial combat that will later prove prophetic when violence erupts within their own group.
Built between 70-80 AD under emperors Vespasian and Titus, the Colosseum hosted gladiatorial contests and public spectacles for nearly 400 years. It could hold 50,000-80,000 spectators and featured complex underground chambers for animals and stage machinery.
A UNESCO World Heritage Site and one of the New Seven Wonders of the World, the Colosseum attracts over 6 million visitors yearly. Extensive restoration work continues to preserve this symbol of Imperial Rome.
Visit: Colosseum (historic site)
Piazza di Trevi — Rome's most famous fountain
The tour group gathers at the baroque fountain where tourists traditionally throw coins for good luck. Alleyn observes the interplay between group members as they participate in the ritual, unaware that luck has already abandoned them. The fountain's crowded setting provides cover for whispered conversations and furtive exchanges.
Completed in 1762, the Trevi Fountain is the largest baroque fountain in Rome, standing 86 feet high and 161 feet wide. The tradition of throwing coins began in the 1950s, inspired by the film 'Three Coins in the Fountain.'
The fountain collects approximately €3,000 daily in coins, which are donated to charity. After major restoration completed in 2015, it continues to be one of Rome's most photographed landmarks.
Visit: Trevi Fountain (landmark)
Piazza San Pietro — Vatican's papal basilica
The tour visits the magnificent basilica where Alleyn contemplates the spiritual significance while remaining alert to the human drama unfolding among his fellow tourists. The sacred atmosphere contrasts sharply with the profane tensions simmering within the group, particularly around their mysterious guide.
Built over the tomb of St. Peter between 1506-1626, the basilica is one of the largest churches in the world. Designed by architects including Bramante, Michelangelo, and Bernini, it represents the pinnacle of Renaissance and Baroque architecture.
St. Peter's remains the papal enclave and a major pilgrimage destination. Visitors can climb the dome for panoramic views of Rome and view masterpieces including Michelangelo's Pietà.
Visit: St. Peter's Basilica (historic site)
Piazza di Spagna — Elegant 18th-century staircase
Alleyn and the tour group ascend the famous steps, where the inspector notes how the elevated vantage point reveals the complex relationships and hidden animosities among the tourists. The steps become a metaphor for the social climbing and pretensions that may have motivated murder.
Built between 1723-1725 to connect the Spanish Embassy with the French church of Trinità dei Monti, the 135 steps were designed by Francesco de Sanctis. They became a gathering place for artists, writers, and Grand Tour travelers.
The Spanish Steps remain one of Rome's most popular gathering spots, though sitting on them is now prohibited. The area is surrounded by luxury boutiques and the Keats-Shelley House museum.
Visit: Spanish Steps (landmark)
Piazza della Rotonda — Best-preserved Roman building
Inside the ancient temple-turned-church, Alleyn marvels at the engineering feat while observing his fellow tourists. The Pantheon's perfect dome and mysterious oculus create an atmosphere where secrets seem to hover in the filtered light, and where the tour guide's nervous behavior becomes more pronounced.
Built by Emperor Hadrian around 126 AD, the Pantheon features the world's largest unreinforced concrete dome. Originally a temple to all gods, it was converted to a Christian church in 609 AD, ensuring its preservation.
The Pantheon remains remarkably intact and serves as a church and tomb for notable Italians including Raphael. Entry is free, making it one of Rome's most accessible ancient monuments.
Visit: Pantheon (historic site)
Via Veneto — Luxury accommodation
Inspector Alleyn stays at this elegant hotel where he can observe the comings and goings of suspects and witnesses. The hotel's refined atmosphere contrasts with the dark undercurrents of murder, and its concierge proves helpful in tracking the movements of the mysterious vanished guide.
Built in 1906 during Rome's Belle Époque period, the Excelsior quickly became a symbol of luxury on the fashionable Via Veneto. It hosted royalty, movie stars, and dignitaries throughout the 20th century.
Now part of the Westin chain, the hotel maintains its reputation for luxury and continues to attract discerning travelers to its prime location near the Villa Borghese.
Visit: The Westin Excelsior Rome (restaurant)
Ancient Roman road — The Appian Way
The tour group ventures out to walk along the ancient cobblestones where Roman legions once marched. Here, away from the city crowds, tensions reach a breaking point. The isolated setting of tombs and ruins becomes the perfect backdrop for confrontation and ultimately, murder.
Built in 312 BC by Appius Claudius Caecus, the Appian Way was Rome's first major highway, connecting the capital to southern Italy. Lined with tombs and monuments, it was where Spartacus and 6,000 followers were crucified in 71 BC.
The first 10 miles of the Appian Way are preserved as a regional park. Visitors can walk or cycle the ancient stones past Roman tombs, including the famous Tomb of Cecilia Metella.
Visit: Appian Way Regional Park (historic site)
Lungotevere Castello — Hadrian's Tomb fortress
The cylindrical fortress looms over the Tiber as Alleyn pursues leads about the vanished tour guide. The castle's history of papal refuge and imprisonment seems fitting for a story where someone has sought to escape justice. From its ramparts, Alleyn pieces together the connections between victim and killer.
Originally Hadrian's mausoleum (139 AD), it became a papal fortress in the 14th century. Connected to the Vatican by a secret corridor, it served as a refuge for popes during sieges and as a prison for enemies of the Church.
Now a museum showcasing Renaissance frescoes, papal apartments, and military history. The rooftop terrace offers spectacular views of Rome and St. Peter's Basilica.
Visit: Castel Sant'Angelo National Museum (museum)
Across the Tiber — Medieval neighborhood
Alleyn follows clues through the narrow medieval streets where the missing tour guide may have sought refuge. The labyrinthine alleys and hidden piazzas of Trastevere provide perfect cover for someone trying to disappear, but Alleyn's methodical investigation gradually closes the net.
Trastevere has been inhabited since Roman times, originally populated by immigrants and workers. Its narrow medieval streets and authentic Roman atmosphere made it a bohemian quarter for artists and intellectuals.
Now one of Rome's most vibrant neighborhoods, Trastevere buzzes with trattorias, bars, and nightlife while maintaining its medieval character. The area attracts both locals and tourists seeking authentic Roman experiences.
Visit: Trastevere Historic District (historic site)
Piazzale Napoleone I — Rome's central park
In the peaceful gardens, Alleyn conducts private interviews with tour group members away from prying ears. The park's romantic grottos and hidden paths mirror the secret relationships and concealed motives that led to murder. Here, crucial confessions emerge among the umbrella pines.
Created in 1613 for Cardinal Scipione Borghese, the villa was designed as a suburban estate with elaborate gardens. Napoleon's sister Pauline Borghese later lived here, and it became Rome's first public park in 1903.
The 148-acre park houses several museums including the Borghese Gallery, plus a zoo, lake, and numerous walking paths. It remains Rome's most popular green space for both recreation and culture.
Visit: Villa Borghese Park (park)
More by Ngaio Marsh: All Ngaio Marsh books
More novels set in Rome: Browse all Rome books on Map A Story
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