Barking up the wrong tree?

Well it's not actually the wrong tree but I have no idea what it is. Very smooth green bark.
We had scampi and chips out at the local just around the corner from mrs b house last night.
This morning we walked it off around Sheringham park and climbed to the top of the observation platform. Beautiful trees and flowering plants within the grounds. Spring is in the air but it was chilly when we viewed the sea from the front at Sheringham.
A very enjoyable two day break away.