The Tropic of Capricorn is the circle of latitude defining the border of the tropics in the southern hemisphere. It is defined by the position of the sun during December (i.e. summer) solstice - at the Tropic, it will be directly overhead at noon. The Australian part north of the Tropic is often referred to as "Capricornia". The construction erected here reminds one a bit of rusty East European WW II memorials.