If you travel from Istanbul to Bulgaria, once you cross the Bulgarian border everything is going to change.The surrounded landscape will become more interesting and in pretty small towns and villages there aren’t concrete blocks, only low, red-brick houses with red roofs and messy gardens.

Then Plovdiv will appeared as a cluster of blocks high-rises trying to reach the red sky. But it would be absurd to judge a city by its suburbs. Over the centuries Plovdiv changed hands between Bulgarians and Byzantines many times until, in the late 14th century, the last, dissolving remnants of the Bulgarian empire were absorbed by the Ottomans.

But, despite this and the best efforts of Communist planners, with their love of concrete and vacuous monumentality, Plovdiv has somehow survived. Walking north along Knyaz Alexandre — Plovdiv’s equivalent to Fifth Avenue –which is much more welcoming square, with busy outdoor cafes and a fountain ringed by bronze swans.

At the end of Knyaz Alexandre is Plovdiv’s Great Mosque, and a huge hole in the ground containing the northern end of a grand Roman stadium. The Great Mosque was a splendid, early Ottoman structure built, as the gravely courteous Turkish, in the reign of Sultan Murat II. Behind the mosque was a small square with yet more cafes and displays of horribly kitschy paintings. A steep, cobbled street led into the heart of the old quarter.

In exploring old Plovdiv, it is hard to go wrong. Just get pleasantly lost, and you are sure to find something enchanting. For example, there is main drag, and soon came upon the Lamartine House, a tall konak painted a dusty pink where the lachrymose French poet had rested for a few nights during the course of his ”Voyage en Orient.” Round a corner and down a steep slope was the Roman theater, its lovely, Ionic stage building hovering above a four-lane highway.

Almost immediately next door was Plovdiv’s Ethnographic Museum. Here, it is the building that houses the collection, rather than the collection itself, that is the chief exhibit, for this is perhaps the most splendid of old Plovdiv’s konaks, which are generally notable for the painted decoration of their exteriors.