A backpack and waist bag carrying system, comprising: a backpack comprising a bag portion attached to shoulder straps (80, 82); the bag portion defining an upper compartment in an upper part of the bag portion and a lower compartment in a lower part of the bag portion, the lower compartment having openings (102, 52) on right and left sides of the lower part of the bag portion; a waist bag comprising a receiver and a waist belt, the receiver being attached to the waist belt whereby right and left wings (180a, 180b) of the waist belt extend away from the receiver; wherein the receiver has a cross-sectional size and shape allowing it to be received in the lower compartment while the right and left wings (180a, 180b) of the waist belt extend through the openings (102, 52) on the right and left sides of the lower part of the bag portion and the lower compartment, whereby the waist belt may be fastened to itself so as to encircle a bearer's waist when the backpack is worn on the bearer's back and the bearer can rotate the waist bag around the bearer's waist, when the backpack is worn on the bearer's back, from a first position in which the receiver is contained in the lower compartment and adjacent the bearer's back to a second position in which the receiver is adjacent the front of the bearer; characterized in that: a door is attached to the bag portion adjacent one of the openings on the right and left sides of the lower part of the bag portion, the door being shaped to cover the one of the openings and having a free end rotatable away from the one of the openings and a tensioning system (130, 132, 134, 136, 138, 140, 142, and 144) to urge the door away from the one of the openings; a buckle comprising first and second interlocking buckle components (194a, 194b), the first buckle component being attached to the door adjacent the free end of the door and the second buckle component being attached to the waist bag whereby the free end of the door may be secured to the waist bag when the receiver is contained in the lower compartment, wherein the receiver of the waist bag is secured in the lower compartment; and wherein the other one of the openings on the right and left sides of the lower part of the bag portion is a slot permitting the waist belt to extend through it but not permitting the passage of the receiver. a backpack comprising a bag portion attached to shoulder straps (80, 82); the bag portion defining an upper compartment in an upper part of the bag portion and a lower compartment in a lower part of the bag portion, the lower compartment having openings (102, 52) on right and left sides of the lower part of the bag portion; a waist bag comprising a receiver and a waist belt, the receiver being attached to the waist belt whereby right and left wings (180a, 180b) of the waist belt extend away from the receiver; wherein the receiver has a cross-sectional size and shape allowing it to be received in the lower compartment while the right and left wings (180a, 180b) of the waist belt extend through the openings (102, 52) on the right and left sides of the lower part of the bag portion and the lower compartment, whereby the waist belt may be fastened to itself so as to encircle a bearer's waist when the backpack is worn on the bearer's back and the bearer can rotate the waist bag around the bearer's waist, when the backpack is worn on the bearer's back, from a first position in which the receiver is contained in the lower compartment and adjacent the bearer's back to a second position in which the receiver is adjacent the front of the bearer; characterized in that: a door is attached to the bag portion adjacent one of the openings on the right and left sides of the lower part of the bag portion, the door being shaped to cover the one of the openings and having a free end rotatable away from the one of the openings and a tensioning system (130, 132, 134, 136, 138, 140, 142, and 144) to urge the door away from the one of the openings; a buckle comprising first and second interlocking buckle components (194a, 194b), the first buckle component being attached to the door adjacent the free end of the door and the second buckle component being attached to the waist bag whereby the free end of the door may be secured to the waist bag when the receiver is contained in the lower compartment, wherein the receiver of the waist bag is secured in the lower compartment; and wherein the other one of the openings on the right and left sides of the lower part of the bag portion is a slot permitting the waist belt to extend through it but not permitting the passage of the receiver. a door is attached to the bag portion adjacent one of the openings on the right and left sides of the lower part of the bag portion, the door being shaped to cover the one of the openings and having a free end rotatable away from the one of the openings and a tensioning system (130, 132, 134, 136, 138, 140, 142, and 144) to urge the door away from the one of the openings; a buckle comprising first and second interlocking buckle components (194a, 194b), the first buckle component being attached to the door adjacent the free end of the door and the second buckle component being attached to the waist bag whereby the free end of the door may be secured to the waist bag when the receiver is contained in the lower compartment, wherein the receiver of the waist bag is secured in the lower compartment; and wherein the other one of the openings on the right and left sides of the lower part of the bag portion is a slot permitting the waist belt to extend through it but not permitting the passage of the receiver.