The Basilica di Santa Maria Gloriosa dei Frari, usually just called the Frari, is a church in Venice, northern Italy. One of the greatest churches in the city, it has the status of a minor basilica. It stands on the Campo dei Frari at the heart of the San Polo district. The church is dedicated to the Assumption (Italian: Assunzione della Beata Virgine).
https://en.wikipedia.org/wiki/Santa_Maria_Gloriosa_dei_Frari
Sam and companions merely passed through by train on their way to Venice, July 20, 1867.
Mark Twain Project: Quaker City Itinerary
Lake Como (Lago di Como in Italian, also known as Lario, after the Latin name of the lake; Lach de Comm in Insubric; Latin: Larius Lacus) is a lake of glacial origin in Lombardy, Italy. It has an area of 146 km², making it the third largest lake in Italy, after Lake Garda and Lake Maggiore. At over 400 m (1320 ft) deep, it is one of the deepest lakes in Europe, and the bottom of the lake is more than 200 metres (656 ft) below sea-level.
Twain made a day-trip from Como to Chiasso in nearby Switzerland, not mentioned in Innocents Abroad (Mark Twain A to Z)
The amphitheatre was built near the Porta Ticinese ("Ticino Gate") in the 2nd-3rd centuries AD, when Mediolanum grew as economical and political importance while Rome declined. It remained in use until the city was one of the capitals of the Western Roman Empire (4th or 5th centuries). Later it was abandoned after Christianism imposed the end to arena games, but also as, in the wake of the imperial crisis, animals to be used in the amphitheatre were no longer imported. It became a quarry for construction stones as early as the 4th century AD, when the Basilica of San Lorenzo was built.
I like to revel in the dryest details of the great cathedral. The building is five hundred feet long by one hundred and eighty wide, and the principal steeple is in the neighborhood of four hundred feet high. It has 7,148 marble statues, and will have upwards of three thousand more when it is finished. In addition it has one thousand five hundred bas-reliefs. It has one hundred and thirty-six spires—twenty-one more are to be added. Each spire is surmounted by a statue six and a half feet high.
The Biblioteca Ambrosiana is a historic library in Milan, Italy, also housing the Pinacoteca Ambrosiana, the Ambrosian art gallery. Named after Ambrose, the patron saint of Milan, it was founded by Cardinal Federico Borromeo (1564–1631), whose agents scoured Western Europe and even Greece and Syria for books and manuscripts.
Santa Maria delle Grazie ("Holy Mary of Grace") is a church and Dominican convent in Milan, northern Italy, included in the UNESCO World Heritage sites list. The church contains the mural of The Last Supper by Leonardo da Vinci, which is in the refectory of the convent.
Bædeker Northern Italy (1877) Route 20 page 128
La Scala (Italian: Teatro alla Scala), is a world-renowned opera house in Milan, Italy. The theatre was inaugurated on 3 August 1778 and was originally known as the New Royal-Ducal Theatre at La Scala (Nuovo Regio Ducale Teatro alla Scala). The premiere performance was Antonio Salieri's Europa riconosciuta.
https://en.wikipedia.org/wiki/La_Scala