In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
--------
Question: Passage: Medieval Kraków was surrounded by a 1.9 mile (3 km) defensive wall complete with 46 towers and seven main entrances leading through them. The fortifications around the Old Town were erected over the course of two centuries. The current architectural plan of Stare Miasto—the 13th-century merchants' town—was drawn up following the Tatar invasions of 1259 and 1287. It features the centrally located Rynek Główny, or Main Square, the largest medieval town square of any European city. There is a number of historic landmarks in its vicinity, such as St. Mary's Basilica (Kościół Mariacki), Church of St. Wojciech (St. Adalbert's), Church of St. Barbara, as well as other national treasures. At the center of the plaza, surrounded by kamienice (row houses) and noble residences, stands the Renaissance cloth hall Sukiennice (currently housing gift shops, restaurants and merchant stalls) with the National Gallery of Art upstairs. It is flanked by the Town Hall Tower (Wieża ratuszowa).
 Link Information: none Answer: none

Answer: How large is the town square of Rynek Glowny?


Question: Passage: De León, a native of Trujillo Alto, Puerto Rico, first won a world title when faced with WBC world champion Marvin Camel on November 25, 1980, at the undercard of Sugar Ray Leonard and Roberto Durán's second fight in New Orleans. De León outpointed Camel over 15 rounds. After he knocked out Camel in 8 in a rematch, countryman Ossie Ocasio won the WBA world title, becoming the second pair of Puerto Ricans to share world titles in the same division at the same time, after Alfredo Escalera and Samuel Serrano had achieved the feat in the 1970s at Jr. Lightweight. De León lost his title in a shocking upset to former Gerry Cooney victim S. T. Gordon by a knockout in round 2 at Cleveland in 1982, and won a comeback fight versus former world Heavyweight champion Leon Spinks by a knockout in round six in 1983. After that, he and Gordon boxed a rematch in Las Vegas, and De León dropped Gordon once in the first round and once in the twelfth, en route to a unanimous decision win in a history-making bout: De León had now become the first boxer to win the world Cruiserweight title twice.
 Link Information: Leon Spinks (born July 11, 1953) Answer: 30

Answer: How old was the fighter that De Leon beat in a comeback fight in 1983?


Question: Passage: Fort Mercer was a fort on the Delaware River in New Jersey constructed by the Continental Army during the American Revolutionary War. Built by Polish engineer Thaddeus Kosciuszko under the command of George Washington, Fort Mercer was built in 1777 to block the approach to Philadelphia, Pennsylvania in concert with Fort Mifflin on the Pennsylvania side. Fort Mercer was located in an area called Red Bank, in what is now the borough of National Park, Gloucester County, New Jersey. The fort was named in honor of Brigadier General Hugh Mercer who had died earlier that year at the Battle of Princeton. The fort's site is now part of Red Bank Battlefield Historical Park, which includes a monument and museum. Several cannons attributed to British warships lost supporting the attack on the fort, and others found buried at the fort itself, are in the park.
 Link Information: A 102.5-mile stretch of this federal navigation channel, from Philadelphia and Camden to the mouth of the Delaware Bay, was deepened to 45 ft Answer: 45 ft,

Answer:
How deep is the body of water near which Fort Mercer was located?