Here are a few suggestions for your next trip from Sliven

In 2 hours, you can reach Burgas, Stara Zagora, Yambol, Kazanlak.

In 3 hours, you can reach Veliko Tŭrnovo, Dimitrovgrad.

In 4 hours, you can reach Plovdiv, Varna, Shumen, Haskovo, Gabrovo, Pazardzhik, Targovishte, Gorna Oryahovitsa.

In 5 hours, you can reach Sofia, Pleven, Dobrich, Asenovgrad.

In 6 hours, you can reach Ruse, Pernik, Kardzhali.

In 7 hours, you can reach Blagoevgrad, Vratsa, Dupnitsa.

In 8 hours, you can reach Montana, Kyustendil.

In 9 hours, you can reach Petrich.

In 10+ hours, you can reach Boekarest, Boedapest, Constanţa, Cluj-Napoca, Timişoara, Craiova, Oradea, Arad, Vidin, Szolnok...