Since it opened in 2000, this sophisticated chocolate-brown den of a restaurant hasn't stopped wowing critics and pedestrian eaters. Almost invisible from the quaint street, Blue Hill grabs your attention with chefs Dan Barber and Michael Anthony's precisely cooked and elegantly constructed food, such as poached duck with a stew of organic carrots and toasted spices; grass-fed lamb loin and braised shoulder as cannelloni with chickpeas and zucchini; and poached cod with bok choy, mushrooms, and tomatoes in a currant and coriander sauce. Foams, purees, vinegars, hot and cold temperatures, hard and soft textures -- these are the contrasting elements that elevate Blue Hill's dishes to delectable heights. Reservations essential. Subway: A, B, C, D, E, F, V to W. 4th St.