East Arrow Bastion, which is located between Hudson’s Bastion and East Demi-Bastion on the north eastern side of Dover Castles outer defences was constructed in the 1790’s as part of a major redevelopment of the castle undertaken by Twiss. It is one of four new outworks which were constructed in this area during this period which were designed to provide gunfire towards the fields to the east of the castle. It has an arrow shaped plan and is accessed via a long tunnel (the East Arrow Passage) which extends under the counterscarp bank starts in the ditch close to the exit from Hudson’s Passage' summarised from English Heritage 2014 Dover Castle Conservation Management Plan.