It has been indicated that it is considered rude to Apparate directly into a private area, such as a home. Dumbledore states in "Half-Blood Prince" that it would be "quite as rude as kicking down the front door". For this reason, and for reasons of security, many homes have Anti-Apparition spells protecting them from uninvited intrusions. The accepted way to travel to a home is to Apparate to a nearby location and continue to the final destination on foot. Apparition is considered unreliable over long distances, and even experienced users of the technique sometimes prefer other means of transport, such as broomsticks. Rowling has stated that Apparating over long distances depends on the skill of the wizard, and "Cross-continental Apparition would almost certainly result in severe injury or death." Indeed, even the prodigiously skilled Lord Voldemort elects to fly back to England after visiting the far-flung Nurmengard.