The buses take a number of routes and have conductors/guides who give a running commentary in various languages and point out the major attractions and a little history as they hurtle around the city. Your ticket lets you on and off at various sites along the way as many times as you like in one day. We found it a very good orientation tool and would use them again. In fact, my 77-year-old mother (active), who travelled with us, was quite taken with one of the guides, who had us laughing the whole time, and she would happily have just driven around the city all day, listening to his amusing anecdotes of London history. Do the river cruise towards the end of the day; it is pleasant to grab a cold drink and collapse in a seat on the boat and view the city from a different and much quieter aspect of the river. There are also excellent photo opportunities of Big Ben and some of the other riverside attractions that you can’t get from the roadways and footpaths.

Beware and check the maps you receive if you pre-book your tickets, as the routes change depending on the season. We waited at the first bus stop for quite a while before we decided we should walk further up, as we could see plenty of buses on the next corner. When we showed the ticket collectors our map, they said we had a summer map with more pick-up points. They quickly swapped our map for a current one, and we set off on our journey of discovery. The buses arrive every 15 minutes at most sites and are easily identified. The maps provided are in a naïve style but are very clear to read, as they are based on landmarks and major roads. There are two major companies that run these buses, but we used the "original" company and found them excellent. If we had been staying longer, we would have purchased a second day (offered for a cheaper rate once you have had a one-day ticket) and done another route or two.

They also have an excellent website, which we discovered just before we left home, that shows some of the routes they offer and a little information about them. Much better than the five-line blurb in a travel brochure.

I hopped off at Buckingham Palace and at Westminster Abbey. The buses come every 15-20 minutes to drop off and pick up new passengers. Many of the buses are open-top so that you can get a better view of the attractions. The guide was very informative and helpful.

The included Thames Cruise on the water was disappointing, went on too long, and was not very interesting for the most part. I was glad when the cruise ended.

A discount is provided if you've taken another Original Tour and have the receipt or if you purchase online. You may purchase tickets either prior to boarding or onboard the bus. Buses come every 15 to 20 minutes during operating hours. Ask when you may board the last bus.