Rome offers history lovers and culture buffs a version of one-stop shopping: here it's possible to visit a 2000-year-old temple used to sacrifice animals in secret, bloody rituals; to dine inside the ruins of the theatre where Julius Caesar was killed; or to visit a sumptuous Roman villa where mosaic floors and frescoed walls are magically re-created before your eyes in a spectacular laser show.
Some of the city's best-kept historical secrets are hidden beneath baroque churches, palaces and piazzas - even banks and government offices. It's also frighteningly easy to walk past arches, bridges and obelisks with their own tales to tell about Rome's colourful history. And many of these places are free to visit.
The Eternal City instantly captured my imagination when I moved here five years ago, and prompted me to develop a travel app. Rome's Ancient Treasures: A Travel Guide takes you inside those tucked-away temples and tombs and gives you the latest news on restorations and highlights you may have missed in the past. The app covers 160 different sites and secrets in total; here's a snapshot of some of Rome's finest.
1. Colosseum underground tour
Already seen the Colosseum from above? Treat yourself to an intimate underground tour of the gladiators' cells, or a slightly spooky tour by the light of the moon during the summer months without the daytime hordes. There's something incredible about walking in the footsteps of the gladiators along softly lit subterranean corridors where both the warriors and wild animals once awaited their grim fate. Piazza del Colosseo; $14.85 for Colosseum, Palatine Hill and Roman Forum; 90-minute guided tours $9.90; bookings +39 06 3996 7700.
2. Villa of the Quintilii The Villa of the Quintilii was once the largest and most spectacular residence in Rome and still offers panoramic views out over the countryside and encroaching suburban sprawl. The second-century AD villa was home to two brothers from the powerful Quintilii family, both of whom were murdered by an ambitious emperor with designs on their luxurious pad. The vast complex once boasted thermal baths, a private aqueduct and a hippodrome for private chariot races. The villa sits between the ancient road of Appia Antica and its concrete cousin Appia Nuova and can be reached by bus, bicycle, or a lengthy stroll along the most famous Roman thoroughfare, the Appian Way, which dates back to 312 BC. Via Appia Nuova 1092 (also accesssible from 290 Via Appia Antica on weekends April-October); $7.45; seven-day pass includes entry to Baths of Caracalla and Tomb of Cecilia Metella; bookings +39 06 3996 7700.
3. Tombs of the Scipioni
The ancient tombs of the illustrious Scipioni family were recently opened to travellers for the first time in 20 years. The tombs date back to the early decades of the third century BC, when the influential consul Lucius Cornelius Scipio Barbato was buried here; they were also the resting place for 30 more family members, including some of the most powerful political leaders in the Roman Empire and the generals who conquered Spain and North Africa. At the centre of the site is a stunning subterranean columbarium where you can also see traces of painted plants and funerary symbols on the walls. Via di Porta San Sebastiano 9; $9.90; guided tours only; open Saturday mornings; bookings +39 06 3996 7700.
4. Pyramid of Gaius Cestius The Pyramid of Gaius Cestius was built between 18 BC and 12 BC as a tomb for Gaius Cestius Epulo, a leading Roman powerbroker with a penchant for staging sacred banquets. The marvellous marble structure is 36 metres high and nearly 30 metres wide and its Latin inscription tells us it was built in 330 days. All the city's other pyramids were destroyed, but this one sits like a precious jewel in the middle of one of Rome's busiest thoroughfares, Via Ostiense. But in a way that adds to its charm. Twice a month visitors can go beyond the thick exterior walls and venture inside the barrel-vaulted chamber to see delicate wall frescoes depicting dancing maidens in the Pompeiian style. Via del Campo Boario; $6.80; open 2nd and 4th Saturday of the month for individuals at 11am and groups at 10am and noon; tours only in Italian; bookings +39 06 3996 7700.
5. Mithraic Temple of Santa Prisca Santa Prisca is an unremarkable church on the Aventine Hill just above Circus Maximus but is well worth a visit if you're intrigued by the secret cults and pagan rituals that dominated ancient Rome. No one is sure when the temple was built, but an inscription inside shows it was in use in AD 202. Beneath the church is a rare temple, where the pagan god Mithra was worshipped with blood sacrifices when the Persian cult swept the Roman Empire between the 1st and 4th centuries AD. Inside is a beautifully preserved sculpture of Mithra killing a sacred bull before the god Saturn, who sits at his feet. Seeing traces of 2000-year-old frescoes on the walls as the guide speaks of men who bathed in the blood of rabbits and roosters slaughtered here is simply amazing. Church of Santa Prisca, Via di Santa Prisca 13; $6.80; open 2nd and 4th Sunday of the month for individuals at 4pm and groups at 3pm and 5pm; tours only in Italian; bookings +39 06 3996 7700.
6. House of Augustus
Long lines gather outside the home of Rome's greatest emperor, Augustus, on the Palatine Hill. Only a handful of people are allowed in at a time and admission is at odd hours. Patience is most definitely a virtue here. Experts believe the four rooms, discovered in the 1970s under the ruins of Augustus's sprawling imperial palace, were part of a small home where he lived when he was simply Julius Caesar's adopted son, Octavian. They are lined with fragments of finely etched frescoes, in dazzling red, white and green and considered some of the finest examples of Roman wall paintings. These evocative rooms give you an intimate insight into one of the greatest leaders of the ancient world. Via di San Gregorio 30; admission included in Colosseum and Roman Forum entry; May-Oct 10.30am-1.30pm Mon, 8.30am-1.30pm Wed, Thu, Sat and Sun; closed Tue and Fri; bookings +39 06 3996 7700.
7. Roman Houses of the Celio Under the Basilica of Saints John and Paul
Before you say "Oh no, not another church", look beneath the Basilica of Saints John and Paul. The church sits on an historic piazza across the road from the Palatine Hill and is named after John and Paul, two soldiers executed for their Christian faith in about AD 362 by Julian the Apostate. But long before their tragic deaths, this site was home to a thriving community dating back to the time of Emperor Hadrian in the second century AD. Here you can scour the remains of beautifully restored homes and taverns with stunning frescoes that will take your breath away. Don't miss the lavish frescoes featuring sea monsters and the fourth-century images depicting a Christian martyr, remnants from when a wealthy proprietor moved in and added thermal baths and gardens. Piazza Santi Giovanni e Paolo 13; $7.45; Thu-Mon 10am-1pm and 3pm-6pm; +39 06 772 711
8. National Museum of Rome Whether it is the re-creation of 2000-year-old rooms, the collection of ancient coins or the fine gold jewellery once worn by Roman aristocrats, the National Museum of Rome has something to turn your head. The museum presents a vibrant picture of how people lived and decorated their homes during the Roman Empire, and its archaeological collection is so large that it is housed in four separate locations across the Italian capital. There are amazing exhibits spanning a period from the second century BC through the fifth century AD, including intricate mosaics, stunning recreations of rooms from Villa Farnesina and the remains of ancient graves. The first floor of the Palazzo Massimo site was recently made over to showcase sculptures, including beautiful copies of The Sleeping Hermaphrodite and Myron's Discus Thrower. On the ground level are the remains of one of the world's oldest calendars, dating back to the Augustan era. Palazzo Massimo, Largo di Villa Peretti; Crypta Balbi, Via delle Botteghe Oscure; Palazzo Altemps, Piazza di Sant'Apollinare; Baths of Diocletian, Viale Enrico de Nicola; Tue-Sun 9am-7.45pm, closed Mon; $8.65 ticket valid for three days at Palazzo Massimo, Palazzo Altemps, Crypta Balbi, Terme di Diocleziano
9. Temple of Portunus and Temple of Hercules Victor The Temple of Portunus, dedicated to the god of the same name, was built at the end of the second century BC or early in the first next to the Tiber River near the famous Mouth of Truth. The temple sits in the lively Forum Boarium, the Roman cattle market, and is looking spectacular after a recent renovation. This area is full of ancient landmarks including the circular Temple of Hercules Victor, dedicated in 142 BC by Lucius Mummius and believed to be the oldest marble building in Rome. It was completely restored under Emperor Tiberius, possibly after the Tiber flooded in AD 15, and probably owes its survival to the fact that it was converted into a church in 1132. Head inside to see Renaissance-era Christian frescoes, and keep an eye out for the graffiti scratched in the temple's rear wall and the hollowed indentations in the steps near the front entrance - a reminder of the ancient games that kept the Romans entertained in moments of boredom. Piazza Bocca della Verità; $6.80; open to individuals 11am first and third Sunday of every month; bookings +39 06 3996 7700.
10. Basilica of San Nicola in Carcere The exterior walls of this 16th-century church are lined with ancient columns in what is a great example of Roman recycling. The basilica, which sits beside the Theatre of Marcellus, was built on the site of three ancient temples and it is well worth heading inside to see the fabulous ruins beneath it, including the huge travertine columns. The temple dedicated to Juno, the goddess of protection, dates back to between 197 and 194 BC while the two others were constructed even earlier during the First Punic War between 264 and 241 BC. There are also human bones sitting in a niche but they seem to come from a much later period. Via del Teatro Marcello 46; $3.10 for entry to underground area; 10.30am-6.45pm Mon-Fri, 10.30am-7pm Sat-Sun; +39 06 6889 2787
Rome's Ancient Treasures: A Travel Guide by Josephine McKenna, produced by Sutro Media, is available for download ($2.99) from the Apple App Store online.