The aim of the research is to examine the context of the Willemsplein development. Willemsplein was a public urban-square
in Dutch colonial era (plein) at Jembatan Merah area. Willemsplein, which in the following time became Surabaya
urban heritage, changes into a private memorial park which is known as Taman Jayengrono (Jayengrono Park). The context
of this park is the most important aspect in the urban-square development because the attainment of the suitability and
continuity of the visual-formal, memory, and meaning of the urban-square arrangement implicitely shows certain character.
The research method is a qualitative descriptive method which is implied to analyze the comparation of the arrangement of
Jayengrono Park in the past and at present in three phases. The first phase is the identification of the chronological formation
of Jayengrono Park by using the analysis technique of the historical period suitability (diachronic reading) towards the phy-sical
arrangement (synchronic reading). The second phase is the identification of the proportion of Jayengrono Park by using
the analysis technique of the measurement of the square-proportion ratio. The last phase is the identification of the place by
using the analysis technique of simulation. The research shows that the Willemsplein arrangement combines the classical
European open-square arrangement of the two development centers in Italy and France through the usage of the sequences of
streets, rivers and bridges and the usage of the street axes as the mathematical result of the square proportion. The deletion of
the intagible identitiy in Willemsplein shows that the character context cannot be attained; or it can be interpreted as the loss
of the identity of the cultural reservation in the development of Jayengrono Park. Concurrently, it means that the development
of Jayengrono Park is merely as an urban green open-square.