Noctilucent clouds over the river IJ in Amsterdam by Jeroen de Jongh Photography

The IJ is a river in North Holland. The actual IJ or Binnen-IJ separates Amsterdam's inner city from Amsterdam North, and was originally an offshoot of the Zuiderzee. The name IJ is related to the Frisian Ae, Ee or Die. This means 'water'.

The Silodam is a breakwater and street in Amsterdam's western port area. The approximately 300-metre-long breakwater protrudes into the IJ. Along the Silodam are two former grain silos that now serve as apartment buildings, including the Stenen Silo, a national monument, and the adjacent Betonnen Silo. Also located here is the 2002 apartment building 'De Silodam', a well-known example of modern architecture along Amsterdam's IJ banks. The Silodam is located in the 'Houthavens Oost' area.

The breakwater was constructed at the end of the 19th century and forms the eastern boundary of the Houthavens built around the same time.

Originally, both silos were to be demolished and replaced by new construction, but the industrial heritage was saved when the Stone Silo was declared a national monument in 1996. At the turn of the millennium, the silos were converted into apartment buildings.

Noctilucent clouds are tenuous cloud-like phenomena in the Earth's upper atmosphere. They are the highest clouds in Earth's atmosphere, located in the mesosphere at an altitude of about 76 to 85 km. They consist of ice crystals and are visible from the ground only during astronomical twilight. They are most often observed during the summer months from latitudes between ± 50° and ± 70°.