It looks like an observation platform? But observing what?!
It isn't very tall (maybe 20 ft) so I wouldn't think it was (for example) on the east side of Eastbourne, as that's flat! Not much of a view from that height.
That's why I thought of somewhere like Beachy Head - it would afford a safe view, withut getting too close to the cliff edge?
What else is there near Eastbourne that people would need to be 20 ft high to view?