Yeah the Hilton Garden Inn and the Rennaissance are the two that are most convenient to walking to Sea World as they're just across the street from the parking lot,this is not a very busy street with heavy traffic so it's very doable,however walking to Discovery Cove just doesn't seem as easy as it's further away and located across the street from the busier Central Florida Parkway.Another hotel that could be considered walking distance is the Hilton Vacation club.