A manhole (100) for subterranean installation is described. The manhole (100) comprises a first chamber (110) arranged to receive storm water and a second chamber (120) arranged to receive sewage water. The first chamber (110) comprises a first inlet (111) and a first outlet (112). The second chamber (120) comprises a second inlet (121) and a second outlet (122). The first chamber (110) comprises a first access port (113) opposed to a first base (114) and a first wall (115) arranged therebetween. The second chamber (120) comprises a second access port (123) opposed to a second base (124) and a second wall (125) arranged therebetween. A first normal N1 to the first base (114) extends through the first base (114) and the second base (124). A sewer network 1000 and a method of installing the sewer network are also described.