We love Greenwich! We've visited three times and definitely plan to go back. It really has everything -- history, art, science, interesting architecture, the vibe of a campus (there are two colleges), The River Thames, boats, walking trails, lawns and gardens, maritime museums, and a (relative) lack of crowds. It's another borough of Southeast London (we live on the border of the boroughs of Lewisham/Bromlely), so it's also very easy and quick to get there.
This picture is taken looking at the Greenwich Observatory Tower from the walkway of the Queen's House. The House was designed in 1616. It's the middle, shorter building in the overview above. It was meant as a kind of second palace. The Queen wanted to be able to see her boat where it was tied up at the river dock and refused to let anything be built between her front door and the river (sounds about right to us). So, that's part of the reason for the extensive lawns of Greenwich.
Of course, Greenwich is important scientifically and for navigators because it is home of the World's Prime Meridian (Longitude 0) and of Greenwich Mean Time. This was pretty much all I'd ever heard about Greenwich before we visited -- and there is so much more.
Greenwich Park is the oldest of London's Royal Parks. Now, as well as being open to the public, it is home to two colleges, the Trinity College of Music and the University of Greenwich. The baroque style buildings are 300 or so years old, and in beautiful shape. What a great place to be a student.
These are pictures of the Chapel. We listed to organ music as we walked around the area -- a student was playing for an examination and doing very well it seemed (as if we knew).
This Baroque style is fascinating. Can't imagine living with it, but, maybe just because it is so different, it is wonderful to look at. This Chapel was especially nice because we were the only visitors; a welcome respite from the more crowded tourist sites elsewhere.