The wartime map shows this pillbox on the shoreline.
The pillbox is mentioned several times in documents related to the Telegraph Bay redevelopment, which was later named Cyberport. First there is the 'Final EIA (Environmental Impact Assessment) Report for Agreement No CE 92/97' which says:
10.5.5.2 To the south of the Telegraph Bay Development site lies the Aberdeen Waterfall and a nearby Wartime Pillbox with an adjacent bunker. Either the Waterfall or the bunker may be disturbed by the proposed Telegraph Bay Development, with the proposed Southern Access Road passing some considerable distance away from them both. Views and access to these two facilities may not be impeded by the Telegraph Bay Development, although clearly when viewed from the south, the Telegraph Bay Development may be seen in the backdrop.
Then the "Environmental Impact Assessment Study Brief No. ESB-044/1999", for the southern access road (the U-shaped road in the satellite view above) includes:
3.2 The Scope. [...] The EIA study shall address the likely key issues described below; [...]
(iii) the potential impacts to the historic military pillbox at the Waterfall Bay.
3.3.6 Impact on Cultural Heritage
The Applicant shall assess any direct and indirect impacts on any sites of cultural heritage, including the historic military pillbox at Waterfall Bay, [...]
If you have any memories or photos of this pillbox, please leave a comment below.