After a little research, taking the River bus was the easiest way to arrive at Greenwich. There's a nice walk up to the Observatory, a bit of a hill, but the path is good. We hadn't pre-purchased tickets as we weren't sure of the weather so we arrived early and headed straight down the path behind the little iron gate below the courtyard of the Observatory itself and took photos on the Prime Meridian there. That started a bit of a stampede as several tour groups also waiting rushed down to see what we were doing! An amusing start to our visit. On opening we walked straight in, got tickets within 5 mins and had an enjoyable morning in the museum there. My husband & I both found it very interesting. He especially like the clocks and telescopes. We both thought it very good value and although there were lots of people there it didn't seem as crowded as we expected. Bathroom facilities were good too. Then a leisurely stroll down the hill to check out all the other things to do in Greenwich.