A drainage system configured to be buried in a permeable ground layer, the system comprising: a tubular cap that comprises an end wall and one or more curved sidewalls that extend from a perimeter of the end wall in the form of a skirt to define a recess within the cap ; a tubular body comprising: an inlet at a first end of the body , receivable within the recess of the cap ; an outlet at a second end of the body ; and a passage to allow fluid flow from the inlet to the outlet ; the system further comprising a spacer arrangement comprising a mounting portion that extends from within the cap , the mounting portion configured to be received within the passage at the first inlet end of the body such that, when the inlet is received in the recess of the cap , the mounting portion locates within the passage at the first inlet end to mount the cap to the body , the spacer arrangement being further configured to space said one or more sidewalls of the cap from the body such that, when the inlet is received in the recess of the cap , a channel is formed between an inner surface of said one or more sidewalls of the cap and an outer surface of the body , whereby fluid is able to flow through the channel to the inlet at the first end of the body . a tubular cap that comprises an end wall and one or more curved sidewalls that extend from a perimeter of the end wall in the form of a skirt to define a recess within the cap ; a tubular body comprising: an inlet at a first end of the body , receivable within the recess of the cap ; an outlet at a second end of the body ; and a passage to allow fluid flow from the inlet to the outlet ; the system further comprising a spacer arrangement comprising a mounting portion that extends from within the cap , the mounting portion configured to be received within the passage at the first inlet end of the body such that, when the inlet is received in the recess of the cap , the mounting portion locates within the passage at the first inlet end to mount the cap to the body , the spacer arrangement being further configured to space said one or more sidewalls of the cap from the body such that, when the inlet is received in the recess of the cap , a channel is formed between an inner surface of said one or more sidewalls of the cap and an outer surface of the body , whereby fluid is able to flow through the channel to the inlet at the first end of the body . an inlet at a first end of the body , receivable within the recess of the cap ; an outlet at a second end of the body ; and a passage to allow fluid flow from the inlet to the outlet ; the system further comprising a spacer arrangement comprising a mounting portion that extends from within the cap , the mounting portion configured to be received within the passage at the first inlet end of the body such that, when the inlet is received in the recess of the cap , the mounting portion locates within the passage at the first inlet end to mount the cap to the body , the spacer arrangement being further configured to space said one or more sidewalls of the cap from the body such that, when the inlet is received in the recess of the cap , a channel is formed between an inner surface of said one or more sidewalls of the cap and an outer surface of the body , whereby fluid is able to flow through the channel to the inlet at the first end of the body . <EOS>