Alexandria was too much like a European city to be novel, and we soon tired of it. So, they take a train to Cairo October 4.

A North African seaport and at the time of Twain's visit, a french colony.  The Quaker City anchored here for five hours on October 15, 1867.  Cholera was reported so no passengers went ashore.

Beirut was technically under Turkish rule was was effectively a British and French protectorate at the time of Twain's visit.  The Quaker City arrived September 9, 1867 and departed for Jaffa six days later.  Many of the passengers began overland journeys from Beirut.  Twain and seven others took the long trip.

Cádiz (/kəˈdɪz/, US also /ˈkeɪdɪz, ˈkæd-, ˈ

The Quaker City dropped anchor in the Gulf of Cagliari, some two miles from the town, at 9:00 p.m. on 13 (not 12) October. Captain Duncan wrote, “An official informed us that cholera existed at Cagliara and that foul bills of health were issued to every vessel leaving— We had heard enough and hastily leaving returned to the ship” (Charles C. Duncan 1867, entry for 13 Oct).

Known as Istanbul since 1939, Twain arrived aboard the Quaker City August 17, 1867.  The ship remained there for two days then continued into the Black Sea.  Eight fellow passengers remained in the city until the ship returned to take on coal August 29.  It remained for 5 days.  Twain was particularly impressed with the Stamboul's bazaar.

The Quaker City made port there July 14, 1867 and Mark Twain spent two days sight seeing before taking the train to Alessandria and Milan. The ship stayed in port nine days before sailing to Leghorn. Twain also passed through this city en route to Florence, with his family in November of 1903 and sailed from there with his daughters after Livy died the following June.

From Baedeker:

Visited by Mark Twain in 1867 and in 1903. He first arrived June 29, 1867 and again October 17. He spent most of the first stop visiting Tangier, the second stop touring southern Spain. He stopped at Gibralter November 3,1903, with his family, enroute to Italy. (Mark Twain A to Z)

They reached Horta early on 21 (not 20) June. Like most of the other passengers, Clemens spent a busy day on shore and probably began this letter when he returned to the ship that evening. Continued rough seas delayed departure for Gibraltar until noon of 23 June.

SLC to Jane Lampton Clemens and Family, 21 and 29 June; 1, 3, and 5 July 1867, Azores, Portugal (UCCL 00139), n. 1. 

Palestine's main Mediterranean seaport, the Quaker City anchored here from September 16 to 30, 1867.

See Bædeker (1898) Route 2 Jaffa page 6

See Bædeker (1876) Route 1 Yâfa page 127

Murray Route 18 page 287

Bædeker, 1867:

Leghorn, Ital. Livorno, French Livourne.

Malaga, Spain, Oct. 17.

The first continental European city visited by Mark Twain. He first arrived on July 4, 1867 as a passenger on the Quaker City and the next day left for Paris. He returned toboard the Quaker City July 13. While there, he visited the zoological gardens and Castle d'If. (Mark Twain A to Z) When the Quaker City arrived in Marseilles on the evening of 4 July, Clemens, Jackson, and Slote left the ship, taking rooms at the Grand Hôtel du Louvre et de la Paix, the largest hotel in the city, on Rue Noailles.

The excursionists arrived at St. George, Bermuda, on the morning of 11 November, planning to depart for New York on 14 November. They had fair weather for most of the Atlantic crossing, including their first two days in Bermuda, but according to Captain Duncan, on 13 November a “hard gale from SW to North West” momentarily imperiled the ship and postponed departure until 15 November.

See     SLC to Jane Lampton Clemens and Family, 26 Aug 1867., Yalta, Russia (UCCL 00145), n. 1.