Detailed Instructions: 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.
Problem:Passage: The first obelisks may start to appear in the later 16th century and it is suggested that the obelisk on Compton Pike is Elizabethan in date. More securely dated is a series of obelisks which start to appear in the 18th century. The first of these was the Wakeman obelisk of 1702 by Nicholas Hawksmoor, which is set in the square at Richmond, Yorkshire. Probably several hundred obelisks exist in the British Isles dating from 18th and early 19th centuries. Most of these obelisks, which are often landmarks commemorate famous people and their achievements. At Stowe in Buckinghamshire an obelisk was erected in memory of Wolfe's victory at Quebec in 1752, while at the death of the Duke of Cumberland in 1765 was noted by an obelisk at Englefield Green in Surrey. Thomas Coke, Earl of Leicester, Coke of Norfolk the farming pioneer has a particularly fine obelisk, set up in the park he created at Holkham in Norfolk. Sometimes an obelisk was used to mark the site of a battle such as the obelisk on the site of English Civil War battlefield at Naseby in Leicestershire. Occasionally obelisks are used as mile markers, as on the Great North Road at a mile from Westminster. In Lincoln an elaborate obelisk was set up on the High Bridge in 1762–63 as a conduit for dispensing water, while Anthony Salvin used obelisks as water fountains on the Belton House estates in Lincolnshire.
 Link Information: commissioned the architect Anthony Salvin to undertake improvements to the Estate in 1838 Answer: 1838
Solution:
What year was the estate where Salvin used obelisks as water fountains built?