Lengo (Guadalcanal, Solomon Islands) has four non-compass directions&colon; landward, seaward, upcoast, and downcoast. Areas of brackish water seaward of the tidal river section are often called estuaries. This fringing seaward reef shelf comprises an area around . Thereafter they disappeared except at the seaward end of the Shannon Estuary. The area covered by the fringing seaward reef shelf is about . At least half the seaward coast has sandy beaches. On the seaward side the floor drops steeply to over . Unlike fringing and barrier reefs which extend only seaward, platform reefs grow in all directions. It is also the most seaward of the South Carolina Sea Islands. The subsided continental crust is marked by normal faults that dip seaward. At the seaward end is a lighthouse. Dropping on its journey seaward, the water in the Kansas River falls less than . It provides South Africa its seaward Special Forces capability. The Queen's Gate on the sparsely populated seaward side saw little use. Artillery was placed on the seaward side.