City parks, as open spaces in metropolitan environments, are well suited to serve as a gathering place for city inhabitants to engage in a variety of valuable activities, purposes, and interests. The presence of open space is a crucial factor in a city’s ability to preserve its ecological sustainability. Gajah Mungkur Park is one of the quite shady parks in the Candi area of Jl. S. Parman, Semarang City. Gajah Mungkur Park is unique and has the potential to become a tourist destination, particularly in support of Semarang’s “Green City”. Actually, Gajah Mungkur Park belongs to the City Government, there are several obstacles faced, the park area has not been arranged, there are no adequate facilities, irregular street vendors, difficult road access, irregular parking areas, limited parks and lack of attention from the government. This service method is carried out with primary and secondary literature studies, observations, data collection, and interviews to strengthen, empower, direct the community or stakeholders to optimize the management of park potential and the environment at Taman Gajah Mungkur. In redesigning Gajah Mungkur Park, the concept of “Hidden Layer of Semarang” is used, namely some details of the arrangement concept ideas that will be applied (1) Vegetation Boundary, the concept of vegetation as a hidden layer which also functions as a buffer for air pollution and vehicle noise, (2) Refurbishing – Revitalize, restore the function of the City Park and take advantage of the existing functions of towers, wells and culinary stalls, (3) Multi-Activity, offering various activities for visitors such as leisurely walks, jogging, family and neighbor gathering areas, (4) Pedestrian Engage, providing more access for pedestrians by providing parking space for vehicles with a proportional ratio, (5) Centralized Plaza, proposes a sunken plaza design concept in the form of an amphitheatre as a center of activity. From the concept of “Hidden Layer of Semarang” where the new garden design is expected to contribute to green open spaces in Semarang. Physical implementation of this concept, this park will be hidden and surrounded by vegetation so that the facilities can be enjoyed by the community when they are in the park. As a result, in order for these activities to be used maximally and sustainably, it is required to build appropriate garden landscape design and strengthen community groups through them.