Above me a velvety night sky full of stars. Concentric circles shimmer. I’m in a vortex. Static but giddy. Drowning in light. It is a beauty that knocks me off my feet.

For days now, I’ve been standing, head knocked back at a curious angle, neck cricked, staring up at apses and arches, mesmerised by sparkling, spangling bits of coloured glass.

The mausoleum is small, dark and intimate. Magical almost. There are deer and doves drinking from water bowls and pools; plants and flowers. Saint Lawrence fairly dances to his flame engulfed griddle, almost eager to be burned alive for his faith. There is no pain, no suffering, no fear. The religious message leaves me cold, but the beauty of the artwork catches at my throat. I could look for hours – if my neck could stand it. I cannot help but think of Van Gogh’s starry sky, and see glimpses of Morris & Co. wallpapers in the tangled vines and curlicue vegetation. Klimt was dazzled by the golds, greens and blues, and Cole Porter wrote his ‘Night and Day’ lyrics after visiting. Its a maelstrom of creative energy.

Stumbling outside, I head next door to the Basilica Di San Vitale, a cavernous space. The mosaics no longer seemingly within hand-reach, recede a little, are more remote. But they still stun. A youthful Christ sits on a deep blue globe, surrounded by a glittering golden backdrop and the retinues of the Byzantine emperor Justinian and his actress/courtesan/empress wife, Theodora. Sex and power at the court of Byzantium, the Lamb of God, Moses and Abraham – it’s a heady mix.

We are in sleepy Ravenna, where bikes outnumber cars and nothing, it seems, ever happens. But for more than seventy years in the fifth century it served as the capital of the declining Roman empire. Then it was ruled by an enlightened Visigoth and after that it became an important outpost of the Byzantine empire. That’s some heyday. As a result it has a legacy of mosaic work without equal anywhere in Christendom.

We are here for a week, there is no need to rush and our days settle into a pattern of mosaics and food, food and mosaics. Morning coffee is taken amongst old men reading newspapers, baristas chatting to locals, and a steady procession of cyclists with grocery bags swinging from the handlebars. Lazy lunches in cosy trattoria follow. Cappelletti (pasta filled ‘hats’) with ragu, with sausage and peas, and plump pumpkin-filled ravioli served in a butter and sage sauce. Accompanied by a glass or two of the local Sangiovese wine. There are also piadine (think pitta bread on steroids) filled with squacquerone (Romagna cream cheese) and caramelised figs or Parma ham and rocket. After dessert and espresso macchiato we give each other a nod -‘time to get back to the coalface’, we say. Mosaic time. We pity the poor souls who do all five world heritage sites in one day.

All roads in Ravenna lead eventually to the Piazza del Popolo, and come aperativo time, that’s where we sit, digesting the day’s mosaics and doing a spot more people-watching. This town is sloooooow. Behind us an enclave of old men sits putting the world to rights. First there were four, gradually their number has swelled to ten. They clap each other on shoulders, laugh a lot, and apologise to the tourist on the next table who is being edged further and further along and out. Groups are dotted all over the square, sitting on benches, eating gelato, standing astride cycles or leaning on handlebars chatting to colleagues, neighbours, friends. An old lady passes clutching the arm of a woman I assume to be her daughter. She must be eighty if she’s a day, but her blonde hair is styled, a beret sits jauntily on her head, and her dangling diamante earings swing as she walks. Passiagata is in full swing.

There is something about Ravenna and it’s not just the mosaics – glorious though they are. Time seems to stand still, people do what they always do and yet centuries have passed and empires fallen within it’s orbit; and those little pieces of coloured glass have sparkled through it all.