If you want to get from Sofia to one of the cities in Bulgaria, the cheapest and easiest way to do this is by intercity bus. Bus transportation in Bulgaria is quite well developed and you can easily reach even the smallest city, and, if necessary, to other European cities.
There are 4 main bus stations in Sofia, from which buses depart in different directions.
You can get to the Central Bus Station in Sofia by metro, for this you will need to make one change at the Serdika station and get off at the Tsentralna ZhP Gara station.
See the official website for bus directions from this station.
Website of the central bus station: Centralralavtogara.bg
You can get to it by bus or subway. If you have chosen a bus, route 84 or 604 is suitable for you, look at Google maps for stops, and if you decide to take the metro, you need to take the Sofia Letishche station (it is next to the T2 terminal) and get off at the Joliot-Curie station , this station is 350 meters from the South Bus Station (Autogara South).
From here, buses leave for Samokov (Borovets), Dospat, Velingrad, Panagoryasche, Devin, Pernik.
The official website of the southern bus station: http://www.avtogara-sofiayug.eu
From the western bus station you can leave for the cities of Pernik, Kyustendil, Blagoevgrad, Dupnitsa, Sandanski, Petrich, Bansko, Razlog, Gotse Delchev.
It is very simple to find it, it is located on Ovcha Kupel Street No. 1
Here you can take a bus to Pazardzhik, Plovdiv, Haskovo, Varna, as well as buses to Istanbul, Czech Republic, Germany, Greece.
Here is the base of the carrier company Union-Ivkoni.
The address of the Serdika bus station: “Princess Maria Louise” street No. 102
Официальный сайт Юнион-Ивкони: https://union-ivkoni.com