MercerBalls: On the wobbly/milennium bridge
MercerBalls: Queueing to get into Somerset House (via a skinny stone spiral staircase!)
MercerBalls: Inside Somerset House
MercerBalls: Human statues outside Somerset House (the first stop)
MercerBalls: Big Ben
MercerBalls: 11 miles at 3.15 a.m.
MercerBalls: The Maggies Centre at the Charing Cross Hospital, Hammersmith
MercerBalls: The Maggies Centre
MercerBalls: Getting a star at the RGS
MercerBalls: Globes at the Royal Geographical Society
MercerBalls: At the Royal Geographical Society at 5.05 a.m.
MercerBalls: The Serpentine Gallery pavilion
MercerBalls: Helen and Val prepare to "write" on the Wellington Arch
MercerBalls: The Wellington Arch
MercerBalls: 15 miles at 6.05 a.m.
MercerBalls: Trafalgar Square
MercerBalls: The London Eye in the early morning
MercerBalls: The Palace of Westminster at dawn
MercerBalls: St Paul's and the Gherkin at dawn
MercerBalls: Night Hikers at the Barbican
MercerBalls: Building by the Barbican with the moon
MercerBalls: Night hikers stream across Finsbury Square
MercerBalls: Liverpool Street station at 8.10 a.m.
MercerBalls: Looking at the City from Tower Bridge
MercerBalls: City Hall - start and finish of the Maggies Night Hike
MercerBalls: Night Hikers on the 9th floor balcony at City Hall
MercerBalls: Looking across the Thames from the top of City Hall
MercerBalls: Tower Bridge
MercerBalls: The finish at the top of City Hall just before 9 a.m.