Being a geography student, I found walking across the prime meridian in Greenwich, London probably more exciting than the average person.
I went to Greenwich in October 2013 (sorry I’m late). We visited Greenwich Park and The Royal Observatory. Greenwich itself is definitely top 5 on my list of my favourite places in London. The buildings are beautiful, along with having great shops, restaurants and pubs. The Royal Observatory gives you a great view over the museum down below and Canary Wharf. There is also a monument outside the Observatory which was a gift from Canada (woot woot!).
Once in the Royal Observatory, you are able to go outside and see the meridian…the best bit! When I was there, there was about a 15 minute wait to stand on the line. That’s right, you have to wait in line to stand on the line, but it’s totally worth it.
There is also a green laser from the main building that shines through London. You can apparently see it at night as far as 36 miles away. I always forgot to look for it though. Have you ever seen it?