The colourful houses lining the cobblestone streets of Old Plovdiv are arguably the city's most recognisable sight. The only thing that can distract from marvelling at their painted façades, projecting bay windows and verdant gardens is the pavement. Polished by the feet of generations of passers-by, it is slippery even when dry, as traveller and historian Konstantin Jireček noted as far back as the late 19th century.

The mansions were built in the 18th and 19th centuries by wealthy Bulgarian, Greek and Armenian merchants, who traded and travelled far and wide within and beyond the vast Ottoman Empire. The architecture reflected the Ottoman fashion of the day: projecting bay windows, ornamental wood carving and overhanging eaves. However, they have their own idiosyncrasies that have led some Bulgarian researchers to label their style Plovdiv Baroque.

The Dormition of the Mother of God Cathedral welcomes you as you enter Plovdiv's Old Town from Cuma Square

The design of the Plovdiv Revival Period houses reflects the society that created them. Built by men with significant disposable income, they provided luxurious living for their inhabitants. People in other cities and towns usually had ateliers and shops on the ground floor of their homes, but the rich Plovdiv merchants were beyond the idea of combining business and pleasure. Their mansions served only one purpose: to impress the visitor while being comfortable for their families.

This was how the distinctive façades of the Plovdiv houses came to be, with their curved bay windows and eaves, bold colours and frescoes of flowers, landscapes and geometrical ornaments. High stone walls surrounded the small gardens, but  at least one side of the house opened onto the street, as the inhabitants obviously wanted to keep up with what was going on in the city.

In the 1960s, a couple of 19th century mansions in Old Plovdiv were demolished. Nobody expected to find a beautifully preserved ancient theatre for 6,000 people underneath. Today it is one of Plovdiv's main attractions and is used as a concert and operatic venue

This was particularly relevant for the womenfolk as, according to tradition, no reputable woman should be seen just walking in the streets, unattended by a male relative. A curious architectural invention, unique to Plovdiv, solved the problem. The klyukarnik is a small projecting bay window at street level which allowed women to keep up with the latest news about town without leaving the comfort of their home. Curiously, Bulgarians all over the country still use the word klyukarnik as a nickname for... Facebook.

The interiors of the Plovdiv's Revival Period houses matched their exteriors in grandeur. A large drawing room took up the best part of the living area, where guests were greeted and entertained in an environment that combined the old and the new. Fine traditional woodcarvings covered the ceilings, but the furniture and the cutlery were imported from the West, while murals of flowers and cities near and far adorned the walls.

These Revival Period houses were built over some medieval fortifications, which in turn were built over the stones of an ancient fortress

The beauty of Revival Period Plovdiv enchants today, but it was not always this way. At the end of the 19th century, Bulgarians became fascinated with Westernisation. Suddenly, the houses of their fathers and grandfathers seemed obsolete, outdated and uncomfortable. Consequently, many houses were demolished or abandoned. By the middle of the 20th century the Old Town was a shadow of its former self, with houses in different stages of dereliction, inhabited only by elderly folk.

Luckily, just at that time the local council recognised the importance of the Old Town and its houses, and started to survey, document and restore them. According to some sources, in the following decades up to 80 percent of the houses in the neighbourhood were restored or built anew. Unfortunately, restoration works were often far from perfect. For example, instead of the original building materials such as clay mixed with reeds, bricks were used for the walls. Some of the restored murals also have nothing to do with the original decorations.

The belfry of Ss Constantine and Helena Church and a small, whitewashed kluykarnik overlook a busy thoroughfare in Old Plovdiv

In spite of these shortcomings, the Old Town of Plovdiv is now a place where the atmosphere of times long gone is still palpable and a significant number of its beautiful houses have become museums and galleries.

The Regional Ethnographic Museum Plovdiv is in one of the Old Town's most imposing buildings, Kuyumdzhiev House. It was erected in 1847 by a wealthy merchant, Argir Kuyumdzhioglu, and makes good use of a natural slope and some medieval ruins that still exist. Its hind wall incorporates parts of medieval Plovdiv's fortification walls and Hisar Kapiya gate. Seen from the front, it has only two storeys, but at the back it has four.

Kuyumdzhieva House has 12 rooms and two drawing rooms decorated with woodcarved ceilings. Its magnificent interior suggests the wealth of its original owners, but the house has seen poorer times as well. At the end of the 19th century it was used as a dormitory for girls, then alternated between a milliner's factory, a vinegar distillation workshop and a flour storeroom. In 1938 its significance was recognised, and the predecessor of today's Regional Ethnographic Museum moved in.

The magnificent Kuymudzhieva House now houses the collection of Plovdiv's Ethnography Museum

The Regional Ethnographic Museum now diligently details the way of life in old Plovdiv, focusing on farming and handicrafts, clothing materials and fashions, furniture and interiors, musical instruments and rites, old photographs, drawings and icons.

Balabanov House is another landmark of Old Plovdiv. It was built by a merchant, Panayot Lampsha, at the beginning of the 19th century, but is known by the name of its last owner, a timber merchant called Hristo Balabanov. It was modelled on the sumptuous residences lining the Bosporus in Istanbul at the time. Balabanov House has all the telltale signs of a Revival Period Plovdiv mansion: large drawing rooms, lavishly decorated spaces and internal staircases.

Unfortunately, the original Balabanov House was knocked down in 1935. It was rebuilt 40 years later using the master construction plans. Most of its rooms are now used for cultural events and exhibitions.

Some houses are well-maintained while others are on the verge of collapse

Next to Balabanov House is the residence of the wealthy Armenian merchant, Stepan Hindliyan. In contrast to Balabanov House, it has mostly remained in its original state.

Hindliyan House is in fact a small mansion-type compound. In addition to the large main house it has service rooms, a dorm for the servants, a laundry and a summer kitchen. Interestingly, it also has a private safehouse in the form of a windowless two-storey building equipped with a heavy door, where the Hindliyan family kept its money and riches.

It was built in 1848 and it had all the mod cons of the time, including an Ottoman-style bathroom, a hamam, with running hot and cold water and a room for the bathers to relax in.

Interior from the mansion of the rich Armenian merchant, Stepan Hindliyan

Most of the rooms are decorated with wall paintings depicting faraway locations that the owner reputedly visited in his business travels. These include Sankt Petersburg, Stockholm, Venice, Lisbon, Athens, the Prince Islands in the sea of Marmara and Jerusalem. Interestingly, the unnamed painter who did the murals seems not to have been to these places in person as their depictions often have little to do with actual reality. One example: Jerusalem appears with a... seafront.

Stepan Hindliyan's family left its opulent residence in 1915 and donated it to 23 Armenian families fleeing from the Ottoman Empire. In 1974 the house was listed, restored and equipped with 19th century furniture.

The gallery dedicated to the art of Zlatyu Boyadzhiev will be a highlight of your visit

Some houses in the Old Town merit a visit not so much for their architecture or interior design but for the artwork they house. The gallery showcasing Zlatyu Boyadzhiev's art is one of them. To bill Boyadzhiev (1903-1976) a naivist would be to downplay the talent of a remarkable painter who depicted Bulgarian life in Plovdiv and beyond. His paintings are explosions of life in bright, pure colours: women chat and pray in quaint chapels; men drink, butcher pigs and go hunting; priests adjure over dead bodies; kids ride sledges in an ostensibly chaotic swirl of dramatic, comic and tragic tales.

The Old Pharmacy is a beautiful little museum that exudes herbs and potions

One of the most pleasant gems of Old Plovdiv is... a pharmacy set in the house of Dr Sotir Antoniadi. From 1872 to 1947 Plovdiv citizens came here to buy medicines prepared by pharmacists with degrees from West European universities. The tiny two – storey house is full of dozens of small bottles, drawers, scales, herbs, books, anatomical models and strange instruments that appear better fit for torture than cure. The house has a miniature yard. With its medicinal flowers and herbs it is as enchanting as the interior.