Boxing Day is a bank holiday so some places will be closed. Restaurants etc, also some shops, but it is also a Saturday so I'm not sure?

If it's a clear day then the London Eye is always worth a visit. There is also a traffic free walk along the embankment - approx 10km

Me49 W45
T15 M13
S11 S8
BD 11/15/11 & 3/27/12
Moved out 4/9/12 Moved back 4/23/12
W working on US 5/20/12 Now Piecing!
May-Oct14 drifting
Dec 14 W agrees to more QT
BD Oct15 ILYBINILWY
W filed 1/25/16