Singapore was the most important British naval base in the Far East. The island itself was heavily defended by many type of coastal artillery guns from frontal assault.
There were a number of pillboxes on the island defending from an invasion
Opposite the island at Pengerang on the mainland in Johore there were some bunkers to defend the entrance to the Naval Base
Kota Tinggi was a back door to Singapore from Johore in Malaya the were a number of bunkers to defend the island from this sector
Several pillboxes defended the road from Mersing on the east coast beach to Kota Tinggi which would lead to Johore Bharu and Singapore