what is your problem with that? i'm still waiting for my 10 downing st tour. i have also been unable to visit the private home of the heads of italy, germany, italy, spain. i did visit the kremlin, had to pay a big fee, only to find that the head of russia lived next door.

white house tours do exist. they are usually given to "special" groups. there are probably about 1-2 hundred of them a year. they are pretty much only allowed when the first family is away. lot of them during the bush administration. as late as the mid 19th C, one could walk up, knock on the front door, and be admitted and see the president(as long as that person be the correct color and sex)