Somewhere to go
Riverside walking beside the Thames Barrier
Thames Barrier Park, Silvertown
A large riverside park on the north bank by the Thames Barrier, with lawns, a promenade above the water and the sunken Green Dock garden running through it. A carer can plan a short there-and-back stroll along the level promenade and stop to watch the river traffic rather than attempt the whole park.
Source: en.wikipedia.org. Check opening times and access before you go.

