Palazzo di Bonifacio VIII

Start with the honest part: this is not Boniface VIII's palace. It is Gregory IX's, and the Boniface name was attached to it in the 1950s by the archaeologist who installed a museum about Boniface inside it. The pope who was slapped here owned a different building in Anagni, now called Palazzo Traietto. The Italian source calls the attribution improper, in those words.

What the building actually is, is better than the label. It is the maius residence of Ugolino Conti -- Gregory IX -- finished within the first quarter of the 13th century, and it is where Gregory and the Emperor Frederick II sat down to dinner together on 1 September 1230 to mark their reconciliation after the Peace of San Germano. Nine years later, after they fell out again, Frederick wrote to the pope that this house proved he had forgotten the poverty of Peter. In 1254 Innocent IV received the ambassadors of the Kingdom of Sicily in these rooms. That is two imperial-papal summits in one building.

The rooms you walk through are the ancient core: wooden ceilings, a great stone arch on half-columns with Burgundian Cistercian capitals, possibly already part of Innocent III's tower house. The friction is stairs -- the operator states plainly that architectural barriers make the building inaccessible to people with reduced mobility -- and that the famous slap happened somewhere in Anagni, not provably here.

Visit if you:

• are interested in the medieval papacy at the point where it met imperial power head-on
• read buildings: this one has been dated at anywhere from seven to fifteen construction phases
• are doing Anagni's cathedral and crypt and want the civil half of the story
• want a museum that has started telling the truth about its own name

Skip it if you:

• have reduced mobility -- the operator says the building cannot accommodate you
• expect the room where Sciarra Colonna struck the pope; that is not established
• want a large collection, rather than a small one inside a remarkable shell

This is not only a museum. The complex also holds the "Suor Claudia De Angelis" nursery school and a guesthouse for pilgrims on the Via Francigena, and it forms part of the Mother House of the Cistercian Sisters of Charity, who have owned it since 1764. Children are schooled and a religious community lives and works on the other side of the walls you are walking past. Keep to the visitor route and keep the noise down.

The two open rooms are the oldest fabric in the building -- wooden ceilings, and a stone arch on half-columns with carved Burgundian Cistercian capitals that may predate Gregory IX. They are not replicas and they are within reach. Do not touch the capitals or lean on the arch.

The honest thing a visitor can do here is get the name right. The building is Gregory IX's palace; Boniface VIII's own residence in Anagni is the one now called Palazzo Traietto; and the attribution that gave this place its name was made in the 1950s and is described by the Italian source as improper. The museum itself has moved in that direction since the 2000s, folding the Boniface collection into a wider museum about the palace. Repeating the older story as fact undoes that work.

Finally, buy the Anagni Pass rather than a single ticket if you are seeing the Museo Archeologico Ernico too. It is the arrangement the operator has set up for exactly that, and it keeps two small museums in the same town viable.

The building is not accessible to visitors with reduced mobility. The operator states this outright: architectural barriers, specifically a flight of steps, mean the structure cannot accommodate people with motor disability or reduced mobility. Check before travelling if this affects you.

The palace is run by ArcheoAres and is open every day, on a four-season calendar. From 1 April to 30 June, Monday to Saturday 9:30-13:00 and 15:00-19:00, Sundays and holidays 9:30-19:00. From 1 July to 10 August, Monday to Sunday 9:30-13:00 and 15:00-19:00, holidays 9:30-19:00. From 11 August to 31 October, Monday to Friday 9:30-13:00 and 15:00-19:00, Saturday, Sunday and holidays 9:30-19:00. From 1 November to 31 March, Monday to Sunday 9:30-13:00 and 15:00-18:00. Last entry is 45 minutes before closing in every season.

Admission is €6.00 full, with an audio guide included, or €9.00 with the Italian-language guided tour. Reduced is €3.00 with audio guide, €6.00 with the guided tour, and applies to 12-18 year olds, Instagramers Italia members, groups of more than 15 paying visitors, and school and pilgrim groups. School groups pay €5.00 with the Italian guided tour. Entry is free, with audio guide or on the guided tour, for children up to 12, residents of Anagni, and people with a disability above 74%.

The guided tour leaves at 18:15 from April to October and at 17:15 from 1 November to 31 March -- note that the free admissions are tied to the tour time, so check which one applies on your date.

The Anagni Pass combines this palace with the Museo Archeologico Ernico on one ticket. Groups can add the Hermes radio-receiver system for €1.50 per person. Tickets can be bought online.

Contact the palace directly on +39 800 266 300 or +39 351 099 2996, or at palazzobonifacioviii@archeoares.com.

The opening calendar should drive the decision, because it changes four times a year and the winter version is materially shorter. From 1 November to 31 March the palace closes at 18:00 rather than 19:00, and the guided tour runs an hour earlier, at 17:15 instead of 18:15. Since free admission is tied to the tour, winter visitors entitled to it need the earlier slot.

Within the day, the long midday break is the thing to plan around: the palace shuts between 13:00 and 15:00 on most days, though Sundays and holidays run straight through from 9:30 to 19:00 from April to October. Last entry is 45 minutes before closing in every season, so arriving at 18:30 in summer is arriving too late.

For atmosphere rather than logistics, early September has an obvious claim: the events the museum interprets -- the arrival of Sciarra Colonna's men at Anagni -- happened on 7 September 1303. Anagni is also on the Via Francigena, and the complex includes a guesthouse on that route, so the walking season brings pilgrims through.

Pair the visit with the cathedral. The Caetani Chapel was added to its south front in 1292 by the same pope this museum is named for, which makes the two halves of one story.