Gave this to my sister and friend as they just had an opportunity to visit NYC this Fall . They immediately started working on the puzzle and completed it within two days. Both are seniors (60's and 70's) and although they said the street names on the base were difficult to read, the puzzle was still very doable. They finished the base the first day and the second layer the next morning, and the buildings that evening. They felt the puzzle was challenging but not impossible, and are very please with the final results. My sister normally does not do puzzles but quickly got caught up with this one and thoroughly enjoyed the experience. They definitely would recommend this puzzle! My sister also liked the historical aspect.