The English Curtain Submarine Mining Observation Post was built on the apex of English Curtain where is joins St Sebastian Curtain. Notes Witten on the plan in respect of English Curtain Battery, UK National Archives, MPHH 1/75, states, “site for S.M. observing station authorized” Malta 5/793 on 17th April, 1900. A similar authorisation was given for the “site of magazine under roadway authorised to be converted into a Test Room”. These two structures would have been used to control the minefield that was laid between Fort Tigne and Fort St Elmo.
The actual mines would have been laid from the Submarine Mining Station in the Valetta ditch.
In about 1936 this area was built over with a Twin 6-pdr gun with three storey control tower built over the site.
UK National Archives MPHH 1/75