Why Singapore was called the 'impregnable fortress' of the British Empire in the East (Before WWII)

Different and large amounts of shore guns for defense, deep Harbour for the stationing of Capitol Ships like cruisers and battleships,a large detachment of soldiers for defense against invaders, tough terrain. "Seven acres at the top of the hill were levelled and seven 68-pound guns were mounted in the field redoubts on the southern end, facing the Straits. Eventually, more that 17 pieces of artillery were mounted. Many other forts and batteries set up to defend the Straits and Singapore town.' showing that Singapore had many equipment to defend itself and that it has very good defense from ' the military forces on the island had been reinforced with the decision to build a great naval base in Singapore. It was seen in reports as "the most secure base south of Hong Kong" and its hinderland was more firmly under British control than Hong Kong's' and 'The British strategy to defend Singapore meant that there was a need for a significant number of soldiers, airmen and sailors to fully defend the newly built base and numbers were gradually increased in the 1930s.' thus being considered as well defended for possible enemy attacks.


Source: Singapore at War