347 Romford Market - South Ockendon covers some pleasant semi-rural mileage

I echo the 275 recommendation - a slightly odd route, but (away from
Walthamstow) often a brisk ride through changing vistas.

What about some of the routes in the Purley/Warlingham/Woodmansterne areas?
This is fairly hilly territory, and I've often thought I could enjoy a ride
on the top deck around these parts, but never made time for it. In fact, any
route recommendations in this area?

Chris