The sound of wailing bagpipes and an accordion greeted me from over the wall. I saw a troupe of girls in swirling green and red dresses dancing hand in hand in their sweltering Bulgarian folk costumes as the temperature hit the high 30s.
I found myself sitting next to Nedelya, one of the dancers. She asked me, as most Plovidians do, whether I preferred Plovdiv or Sofia. I didn't have to lie because for me there was no contest: Plovdiv. The result was handshakes and an invitation to her name day party.
Here in the country's cultural capital the creative spirit burns white hot. The more savvy travellers on easyJet's new flights to Sofia, starting on Tuesday, will continue on their journey to this city of painters, musicians, dancers, writers, awkward politicians, gorgeous buildings, fine food and wine, which has always had a bohemian edge. Ever so politely it put two fingers up to the Ottomans, then to the communists, and now to Sofia. Yet it's always been the most welcoming of places to outsiders who meant no harm. Locals believe above all that life is for enjoying – but without too much effort. That's why they're called the Ailyaki, the idle ones.
I ventured out on to the treacherous cobbles of the Old Town and made for the Roman amphitheatre. On stage they were getting ready for an opera that evening, Aida. Through the backdrop of the ionic colonnade I could see the modern city, and beyond that the Rhodope Mountains.
The Old Town, built on three hills rising out of the plain, is a marvel. Thracian, Greek and Roman remains lie next to, and beneath, 400 Revival-style houses, those 19th-century wooden-frame constructions built by the emerging class of rich Bulgarian merchants who eventually saw off the Turks. Art is everywhere: as many as 30 top-notch galleries and studios are tucked into alcoves, while music pours out of countless doorways.
Down below, a mile-long pedestrian street lined with shops stretches from the Maritza River to Tsentralen Square. It makes Plovdiv a place of walking and talking. Beneath much of it runs a Roman stadium, which emerges in bizarre settings, not least at an internet café whose clients look out at an archway where lions once roared. And then there are the shops, cafés and bars of Kapana, the old Turkish quarter – masses of them and all ridiculously cheap.
Nedelya's party guests and I were taken to the folklore restaurant Veseloto Selo (Happy Village). About 30 of us were soon surrounded by plates of shopska salad, bottles of rakya, huge earthenware pots of stew, and bowls of yoghurt.
I got talking to Nedelya's artist brother. "I bet your friends in England don't know where Thrace is," he said. "Tell them to come. They can help us discover our past. Orpheus was a Thracian, and so was Spartacus. Maybe that's why we're such a rebellious lot."
"And why do Bulgarians shake their heads for yes and nod for no?" I asked.
"We wanted to confuse our oppressors," he said. "Now we just carry on."
How to get there: EasyJet (easyjet.com), WizzAir (wizzair.com), BA (0870 850 9850; ba.com) and Bulgaria Air (020-7637 7637; bulgaria-air.co.uk) all fly to Sofia. From the airport take a taxi to Plovdiv for about 70 leva (£25), or to Sofia bus station (£2), then a bus to Plovdiv (£3.60). Robert Nurden stayed at the Hebros Hotel (00 359 32 260180; hebros-hotel.com), in a double from ¿95 a night, with breakfast.