The travel memoir was a staple of 19th century literature, many published accounts, both book length and in magazines. Southern Europe was of great interest in Britain-- there's a great deal of attention to Greece and its revolution, and that interest extends to what was sometimes called "Turkey-in-Europe" and its Balkan frontiers.

See Tim Youngs, ed. Travel Writing in the Nineteenth Century: Filling the Blank Spaces (London:2006) - there's a chapter in it "The Balkans in Nineteenth-Century British Travel Writing" which is a comprehensive review of the subject.

Offhand, a few listed in bibliographies:

Mackenzie and Irbie, Travels in the Slavonic Provinces of Turkey-in-Europe, London:1867

Galton, Francis, ed. "Christmas in Montenegro" in Vacation Tourists and Notes of Travel in 1860, London 1862

Pouqueville, F.C.H.L. Travels in Epirus, Albania, Macedonia, and Thessaly. (London:1820)

Holland, Henry. Travels in the Ionian Isles, Albania, Thessaly, Macedonia, &c. During the Years 1812 and 1813 (London:1815)

Spenser, Edward. Travels in European Turkey, in 1850 Through Bosnia, Servia, Bulgaria, Macedonia, Thrace, Albania, and Epirus (London:1851)

Evans, Arthur. Through Bosnia and the Herzegóvina on Foot During the Insurrection, August and September 1875. (London:1876)

Lavallee, Joseph. Travels in Istria and Dalmatia Drawn Up from the Itinerary of L. F. Cassas. (London: 1805)

Hobhouse, J.C. A Journey Through Albania, and Other Provinces of Turkey in Europe and Asia, to Constantinople, During the Years 1809 and 1810. (London:1813)

Just a small selection of book length material. Because they're all out of copyright you can typically find full text at Google books or archive dot org. If you can read German there would be many more, probably some number in French, Italian and Russian as well, though I can't comment on that.