The Big Ben bell is an amazing sight with the four smaller bells all round, a really nice SL build, the architecture is stunning as well, not to mention the view from up there is worth going to see in itself. I noticed there was a staircase behind me so I went down to see what else I could find.
The room below takes you behind the actual clock faces and the detail is fantastic, plus you can still see the lovely view of the Thames and surrounding London buildings through the ornate dials. Take some virtual sandwiches and a flask of tea and stand out on the balcony and admire the reflection on the Thames at sunset, you'll be glad you paid Big Ben (or The Clock Tower!) a visit.