At first glance, the Gràcia district of Barcelona appears to be the gatekeeper of the resurgent Catalan identity: “Free Catalonia!” graffiti scrawled in the backstreets, Catalan flags flying from so many balconies, the distinct sound of the Catalan language heard in cafés and eateries.

A bodega can be a corner store or a corner bar, or sometimes even a wine cellar with a small kitchen serving refined riffs on traditional Spanish foods. In Barcelona, a bodega is all of these, but most of all it is the beating heart of the neighborhood.

QUICK BITE: Spend the day eating your way through Sants, a lesser-explored neighborhood with a booming local food scene and an interesting history. We’ll dig into markets and old vermuteria, pastry shops and down home restaurants, but we’ll also find the pulse of Sants in some contemporary culinary projects.

Our “Culinary Secrets of the Old City” walk goes beyond the major monuments and into the backstreets where all of the serious eating is done. We’ll set off through the atmospheric, lesser-explored market streets around the Egyptian Spice Market and then go deeper into the untouristed Fatih neighborhood.

Up in the high streets of the Horta-Guinardó hills, not far from the old historic building of L’Hospital de La Santa Creu i Sant Pau, there is a restaurant with a big concentration of culinary talent but just eight tables. To make things worse, they are only available during two hours for lunch. Fortunately for those who can’t snag one of those precious tables, La Cuina del Guinardó (“Guinardo’s Kitchen”), a Catalan traditional market-cuisine restaurant, is also a store selling cooked food to take away from morning to evening and a great wine shop, with a tasting area in the upper level.

The subject of frequent arguments over who actually invented it, baklava has a history as multilayered as the flaky dessert itself. The story may actually go all the way back to the 8th century BCE and the Assyrians, who layered bread dough with chopped nuts and honey and baked the result – a kind of proto-baklava – in wood-burning ovens. Perhaps carried by the winds of trade, different versions of this ancient dessert appeared on Greece’s shores a few centuries later. The 3rd-century-CE Deipnosophistae ("Banquet of the Learned") – sometimes referred to as the oldest surviving cookbook – provides the recipe for gastrin, aka Cretan “Glutton Cake,” a sweet that also seems to presage the arrival of baklava as we know it. The instructions, attributed to Chrysippus of Tyana, one of the leading dessert experts of antiquity, calls for turning various chopped nuts, boiled honey and poppy and sesame seeds into a paste which is then spread between two sheets of thin, rectangular dough. At a certain point, ancient Greek cooks started using thinner sheets of pastry, better known as phyllo – Greek for “leaf” – getting closer to today’s baklava.

Some islands, Mykonos and Santorini for example, are known for their temples of gastronomy. Others, like Tinos, Milos, Syros and Sifnos, possess solid reputations for uniformly excellent tavernas. Until recently, Andros, a green anomaly in the treeless, windswept Cycladic chain, had two main attractions for tourists: a world-class modern art museum and a network of well-maintained hiking trails. You could get a decent meal after you’d seen the exhibition in Hora or trekked up to a 1,000-year-old monastery or down a river lined with water mills, but it wouldn’t be something to write home or tweet about.

Following a tip, we set out one morning to find Pamuk Usta, a legend among the chickpea breakfast-wrap-eating Antep-Birecik-Nizip diaspora of Istanbul.

It’s October and mushroom season in many parts of Europe, but if you were hoping for anything like Genoa’s Porcini Festival in Athens, you’re out of luck. But don’t despair: ‘shrooms, wild and cultivated, can be found; it just takes a little sleuthing.

On recent visits to Madrid, we’ve noticed that a new breed of food market has taken hold of the city’s attention. While the traditional kind with food stalls slowly disappears, vibrant, culture-focused gastromarkets are booming. In addition to great food, they offer a mix of businesses, along with cooking demos, live music, exhibitions – the list goes on. In 2009, the private society El Gastródomo de San Miguel refurbished a beautiful building that was built in 1916 and located very close to Plaza Mayor. It was opened as the “culinary space” Mercado de San Miguel. Though the initial inspiration was Barcelona’s La Boquería, San Miguel is utterly different, with its own colorful, unique personality. The market is dedicated not just to selling quality seasonal foods, but also to allowing visitors to enjoy them in situ, at tables and chairs distributed throughout common areas. They can choose from cod, fresh shellfish and other seafood, various vermuts, pickles and olives, paella, churros, Spanish wines, international beers, delicious Iberian ham and cured sausages and cheeses, ice cream and non-Spanish items, such as pasta or sushi. Unsurprisingly, the concept has been a hit, and other similarly styled markets have since popped up around the city.

In Catalonia around the summer solstice, we make one of our most traditional liqueurs, ratafía, for which the herbs, fruit and flowers that are macerated in alcohol must be collected on Saint John’s Eve, or June 23. This highly aromatic digestif has long been believed to have medicinal properties. There’s even an old Catalan rhyme along those lines: Ratafía, tres o cuatro al día (“Ratafía, three or four per day”). Different versions of the liqueur have been made for centuries in eastern Spain and some regions of France and Italy but, like the other herb liqueurs throughout Europe, they originated from the Ancient Roman and Greek custom of macerating fruit and herbs in wine, from Arabian perfume distillation and from the sophisticated medieval distillations in monasteries and convents that created the first aguardientes, or grape-based, medicinal liqueurs.

Churros, the long, skinny, crenellated, sweet fried crullers made from just flour, water and salt, have been enjoyed for centuries in Spain, with hot chocolate and without. However, in Barcelona, xurros, as they are called in Catalan, are becoming an endangered species. In recent years, more than half of the xurrerias in the city have disappeared. Many of the old-timer xurreros who still survive have the odds stacked against them: permit renewal for a street stall is near impossible; rent has become prohibitively expensive and continues to increase; or required updates to old infrastructure might prove extremely costly. However, we know of one young newcomer who has emerged with fresh energy and inspiration, incorporating lessons from the masters in his creative take on xurros. The best way to save this endangered species is to eat it, so here are our five favorite xurrerias, which make these star-shaped doughnuts with great care – and with delicious results that are worth seeking out.

Editor's note: For our last stop on CB's Global Bar Crawl this week, we're pulling up a stool at our favorite mezcal bars in Mexico City, kicking back and savoring every last drop. Para todo mal, mezcal. Para todo bien, también. Y si no tiene remedio, tómate litro y medio. For everything bad, mezcal. For everything good, the same. And if that doesn’t help, drink a liter and a half. – Popular saying among mezcal lovers.

Editor's note: Our third installment in the Global Bar Crawl takes us to Barcelona, where gin continues to be the drink of choice among locals. Tomorrow we head to a spot in Istanbul where you can spend an evening visiting a number of bars, all without leaving the building. Spain is a country that loves a long-drink – alcohol in combination with a soft drink, refreshing and open to invention and reinvention. On the heels of creative gastronomy’s efflorescence in recent years, many old drinks, cuisines and forgotten ingredients have returned, revived through new and more sophisticated techniques and interpretations. The gin and tonic, called gintonic here, is one such Spanish obsession, and all that ingenuity and focus have gone into taking this highball to the next level.

Editor's note: In a recent New York Times article, Joshua Hammer wrote about a tour that Nobel Laureate Orhan Pamuk gave him through the author's native city and his personal history there. We were delighted to read that one of Pamuk's favorite places is Vefa Bozacısı, which is one of ours too (and also a stop on the Old City culinary walk). After our first taste, we were not quite ready to sing the praises of boza, a thick, almost pudding-like drink made from fermented millet. But the experience stuck with us. What is that flavor? Something like cross between Russian kvass (a fermented drink made from rye bread) and applesauce may be the best way to describe it. As it did to us, the drink may haunt you, much like the call of the itinerant boza vendors who wander the streets of Istanbul during the winter months calling out a long, mournful “booooo-zahhh.”