We'd been up on this tower last year and discussed whether this was a trig or just decoration and decided on the latter. I remember these structures going up in the 80s when the park was being created.

Some weeks ago we were out at the park as the Olympic cauldron had been lit for the London games so during a Munzee hunt we grabbed this one.

Anyway it's since been published as a trig so it MUST be a trig!