The bus tour of Edinburgh is, as like most large cities, a double-decker bus tour. The price is 9 pounds (you can use public transport without limit for 3 pounds, but you have to know which bus goes where and when) and ensures you will not lose time and passes major attractions in the most direct way. The bus goes every 20 minutes 9 am - 4 pm and there's a small discount for students. It goes past the castle, Holyroodhouse Palace (the Scottish Buckingham Palace since the queen stays here and it was Mary Stuart's), then turns around Princes Street and Commercial Street for shopping. Then the new city, a UNESCO heritage site, the royal mile (a mile of the finest shops) and parliament (an architectural curiosity that deserves a look).