This page focuses on the neighbours of the country of Bulgaria. In total Bulgaria has 5 neighbours, these are:

The borders are illustrated in this image, which is adapted from the map of Bulgaria available on Google Maps Bulgaria Map Neighbouring Countries

We now discuss each of these in turn:

Bulgarian/Greek Border
The Bulgarian/Greek border runs for a total of 494KM. This border is to the south and south-west of the country. Looking at the border you could say that it flows west to east. The Belasitsa mountain range acts as a natural divide between the two countries and are to the west of the border range. The Rhodopes mountain range start to the east of the the Belasitsa range and cover the vast majority of the remainder of the border The Maritsa river is to the far eastern end of the border and acts as a natural divide.

Bulgarian/Macedonian Border
The Bulgarian/Macedonian border runs for a total of 148KM. This border is to the south-west of Bulgaria. This border flows in what can generally be described as a north to south-east general direction. The entire border is covered by the Belasitsa/Osogovo mountain ranges, which also incorporate the Vlahina mountains.
Bulgarian/Romanian Border
The Bulgarian/Romanian border runs for a total of 608KM and is the longest border that Bulgaria has with a neighbouring country. The border runs in a west to east direction. The Danube river acts as a natural border for 464KM. The last 144KM is to the east of the border and is borderland in the province of Varna, this border stretches all the way to the Black Sea.
Bulgarian/Serbian Border
The Bulgarian/Serbian border runs for a total of 318KM. The border runs in a line, which is more or less north to south to look at. The Balkan Mountains cover the whole border length and includes peaks such as Ruy, Midzor and Vrashka Chuka.
Bulgarian/Turkish Border
The Bulgarian/Turkish border runs for a total of 240KM. The border runs west to East. The Border starts with the Maritsa River in the West The Border continues with the mountain ridges of the Derventski Heights and Strandzha Mountain The border finishes at the mouth of the Resoska River in the East