Nearly every member of the British royal family has learned to swim in the secret indoor pool.

Among Buckingham Palace's mysterious 775 rooms is a swimming pool, where heirs have reportedly learned how to swim

Members of the British royal family from Prince Philip to Princess Diana have enjoyed swimming laps in the private

King George VI commissioned the construction of the pool in 1938 as he was adjusting his family to its public role

In summer 1938 it was decided to build 'a swimming bath and squash court on the north side of the Palace in one of Nash’s conservatories

In 1938, architect James Jack Roberts drew up plans for Buckingham Palace's north-west pavilion to be converted into a pool

The surprise was a new swimming pool, which was specially constructed for the two little princesses so they may have their weekly swimming

The report continued, "The pool will, it is hoped, be ready for the princesses to have their first swim in it in the spring