"?" (Serbian: Кафана „?” / Kafana „?”, Кафана „Знак питања” / Kafana ”Znak pitanja” or Кафана „Упитник” / Kafana „Upitnik”) is the oldest traditional tavern (kafana) in Belgrade, Serbia. Located at 6 Kralja Petra Street, the building is nearly 200 years old. One of the city's best known landmarks, "?" offers traditional Balkan cuisine with starogradska music played.
The building, in which the kafana is located, was built in 1823. It was built by the diplomat and merchant Naum Ičko, on orders and with funds provided by the Prince of Serbia Miloš Obrenović I. Ičko was son of Petar Ičko, a noted diplomat. It was designed by an unnamed Greek architect. Later Prince Miloš awarded it to his personal doctor Toma Kostić known as Ećim Toma for his efforts during the Second Serbian Uprising. Realizing its favourable location, Ećim Toma soon converted the property into a hospitality establishment that became known around town as Tomina kafana, "Ećim Toma's kafana". During early 1830s, the kafana was frequented by famous Serbian linguist and language reformer Vuk Stefanović Karadžić.
In 1878, kafana's name got changed to Kod pastira ("Shepherd's"). It got its present unusual name in 1892, during a dispute with the Serbian Orthodox Church authorities over the new owner Ivan Pavlović's intention to change its name to Kod Saborne crkve (By the Saborna Church), which the church authorities vehemently protested, not keen on seeing the cathedral referenced as part of a kafana's name. So, as a temporary solution, the tavern's owner put a question mark on the door, and it soon became the official name of the place. For a while, out of respect for the nearby church, smoking was prohibited inside the tavern, but this didn't last.