The Private Train 0f Pope Pius IX

Map
In 1849, on a visit to Naples, Pius IX (r. 1846-78) became the first pope* to travel by train. He enjoyed the experience so much that on his return to Rome he promoted the growth of the railway network in the Papal States.   
In 1858, Pius IX received a train as a gift from two railway companies.  On July 3rd 1859, Pius IX made his first journey on the train, travelling from Porta Maggiore to Cecchina, a distance of 16 miles. 
The Chapel Carriage, Private Train of Pope Pius IX, Centrale Montemartini, Rome
The Chapel Carriage
In addition to the engine, there were three carriages: the partially open first carriage was used for papal blessings, the second carriage was reserved for the pontiff's personal use, while the third carriage was a chapel on wheels. The richly ornate exterior of the chapel carriage sports a quotation from the bible (Luke:3:5): ERVNT PRAVA IN DIRECTA ET ASPERA IN VIAS PLANAS ('And the crooked shall be made straight, and the rough ways shall be made smooth', KJV). ​​
The three carriages, which are the oldest surviving railway vehicles in Italy, are on permanent display in the Centrale Montemartini. 

*The predecessor of Pius IX, Gregory XVI (r. 1831-46), was not a fan of railways, blocking their expansion into the Papal States. He is reputed to have remarked: 'Chemin de fer, chemin d'enfer'.  ​