We lived in Jerusalem for a few years when I was a boy and what I remembered most, after we left, was the light. This wasn't the flat light, too vapid to even throw a shadow, of Southern California, where we moved next. Or the bluish-gray light of winter in Wisconsin, where we settled. No. The Israeli light was dense and golden, and it kept deepening during the day, until dusk, when it set all the stone buildings on fire.

Although I returned to Israel several times as an adult, my visits were always limited to Tel Aviv, so I never saw that light again until I spent a week in Jaffa this fall. Jaffa is the sister city to Tel Aviv, sitting so close it's hard to pinpoint the precise border where the cities merge. But they are very different places.

Tel Aviv is all busy momentum and thrusting energy; its high-rises frame its white Bauhaus core and its network of tech companies strain toward the future.

Jaffa, a biblical port, is content instead to hug its core of ancient bones, a magnificent ruin of limestone buildings that soak up the Mediterranean sun. And then there is a deeper difference. One of the most integrated cities in Israel, a mix of Jews, Arabs and Christians, Jaffa is a cultural fusion. Churches and synagogues sit alongside mosques; the Muslim call to prayers floats over the pitted rooftops; hijabs pass yarmulkes on the cobbled streets.

At the casbah

The mix of faiths is most evident in the city's sprawling flea market, a casbah where I spent my first few days in town. The market vendors, hawking a jumble, don't bother to segregate their tchotchkes. Their stalls are piled with menorahs, caftans and big baroque crosses studded with gemstones; there are antique candelabras and mezuzahs.

The scenery surrounding the market is timeless. Old men sit on the streets, mending oriental rugs, under the crumbling stone buildings that have turned furry, sprouting long vines and tufts of weeds. And hanging like fringe in the food stalls are baskets of Jaffa oranges. True to their reputation these aren't the mealy, spud-like oranges that pile up in U.S. groceries. The most orange of oranges, the Jaffa breed spits a geyser of sweet juice the minute you bite into them.

The fruit is an emblem of Jaffa's tireless hunger and a city devoted to the 24-hour nosh. Bakeries like the famous Abulafia, sitting near the city's central Clock Tower Square, sell an endless run of rugelach, bagels and babka through the day and the hummus cafes are open from early morning until the food simply runs out. Sometimes there's nothing left by early afternoon and it's easy to see why. At the famous Abu Hassan, the masabacha plate features whole cooked chickpeas riding on top of the creamy hummus, and the line of Arabs and Jews mingling out front reaches epic lengths on Fridays, before the Sabbath.

I took to grabbing lunch, though, along the oceanfront promenade that connects Jaffa's marina to Tel Aviv's ribbon of seaside high-rise hotels. Once Jaffa's ancient port, where Jonah set off for his fatal encounter with the whale, according to the Bible, the marina is now lined with a string of al fresco cafes plating the freshest daily catch. I table-hopped my first few days in town until I found my favorite, the Container, where the fisherman ceviche was a plate of fresh daily fish roused by coriander, purple onion and chili, and the beetroot carpaccio came dressed with root vegetables, walnuts, Parmesan and balsamic.

Modern touches

The chic seafront bistros are the first hint that Jaffa is much more than a time warp. If the city is one part pure ancient biblical fantasia it is also increasingly morphing into a downright stylish port showcasing 21st-century attractions. At the Design Museum Holon, a futuristic steel structure wrapped up in ribbons of auburn steel, like a peeled orange, the changing exhibits are devoted to industrial fashion and fashion design; the day I stopped by, the gallery was honoring Dutch designer Maarten Baas.

At the Clore Garden of Science, the place to bring the family if you're traveling with kids, the outdoor museum features a water sprinkler that surrounds you in a full circle rainbow, and an exhibit that simulates walking on the moon.

For adults, Jaffa's growing range of contemporary attractions include Beit Kandinof, a hipper-than-thou funhouse complex featuring an art gallery, artists' studios, bar and cafe, plus — why not — the ultimate on-trend attraction: a tattoo parlor.

Another symbol of Jaffa's sudden emergence as a style center is the recent debut of a trio of boutique hotels. The Setai, looking out on Clock Tower Square, sits in a renovated Ottoman fortress turned prison; now its 120 uber-chic guest rooms circle a central courtyard, and its infinity rooftop pool looks out over the seafront. In the revitalized American-German neighborhood, on the border between Tel Aviv and Jaffa, the Drisco hotel is a redo of the area's first luxury hotel, opened in 1870. And at the crown of a hill, the Jaffa Hotel has turned a 19th-century former hospital into one ambitious urban resort. Featuring a spa, fitness center and South Beach-worthy outdoor pool rimmed by loungers, the 127-room hotel is designed as a one-stop refuge. Its contemporary Italian restaurant extends out into a leafy courtyard and the former hospital's chapel has been revamped as a lounge-cum-bar, its crayon-colored settees and poufs sitting under a vaulted ceiling and stained glass windows.

I opted for the Drisco, because it was the most affordable of the three, but splurged my last night at the Jaffa, where my room in the hotel's original, 19th-century wing was all minimalist elegance, framed by the arched windows. The best surprise was in the hotel lobby, where a Damien Hirst spin painting stared down at an exposed stone wall. "It's the remains of a 13th-century Crusader wall," the concierge told me. "We found it when we were restoring the property."

The preserved wall echoes the mission of all the new hotels, and Jaffa itself; the city's leap toward the future is always balanced by a pure reverence for the past. And its dedication to preserve its historic legacy, and oldest bones, is what will save Jaffa from becoming another generic, over-gentrified hipster zone of selfie sticks and influencers.

Nighttimes in the city

That deft balance is most noticeable in the evening, when Jaffa's ancient alleys are strung with fairy lights. By late afternoon crowds of people come out to promenade, filling up the cafes and bars that spill out into the winding walkways so that the whole city becomes a rambling al fresco street party — one part biblical fiesta and one part pagan bacchanalia.

My favorite perch was at Onza, the kind of restaurant that makes you feel that you're at exactly the right place at the right time. Like most of Jaffa's cafes, the Onza dining room proper is tucked into another crumbling stone building but the best tables sit outside, in the side street, and are jammed before the fairy lights even flick on, with young Israelis wearing next to nothing, just filmy tank tops and summer slip dresses that seem ready to float away. The Onza menu mirrors the top note of easy sensuality. Every night I sampled something new. There was a smoked eggplant robed in silky tahini and studded with pistachios. A sea bass filet shared a plate with chickpeas, okra, tomatoes, spinach and parsley, and a seafood hanina was a heap of shrimp, calamari, mussels, tomatoes, zucchini and coriander.

By Thursday, my last night in town, the cafe's seats were taken by midday, a scramble before Shabbat, so I raced while the sun was still shining, grabbed a chair at the end of a long communal table, and plowed through Onza's seamless dish of fried cauliflower, tahini onions, almonds and lemon, maybe the only dish worth justifying the cauliflower trend. It was enough of a feast but my server, a young girl who had immigrated with her family from Russia, wasn't satisfied. "You need to try dessert," she said. So I lingered until dusk, long enough to see the primordial stones of the alley flush gold, just the way I remembered.

Food and travel journalist Raphael Kadushin regularly writes for Condé Nast Traveler, National Geographic Traveler and other publications. In the Star Tribune, he last wrote about Prague.