Finding the best tacos al pastor in Mexico City is akin to finding the best baguette in Paris. There are so many places of exceptional quality; the differences come down to stylistic nuances in flavor and preparation. The best taco al pastor in Mexico City is the closest taquería nearby above a minimum quality threshold that's open late-night. Fortunately, the city is full of such restaurants. One of them is El Charco de las Ranas, or "frog's puddle." It's a sit-down restaurant as opposed to a street-side taco stand. The authenticity police might get angry that real tacos are to be consumed sitting down, but rest assured this is the real deal. There's a full kitchen in the back with a fire-roasted rotating pork spit by the door. The smell of roasting pork permeates the entire restaurant.