The core of the intervention area is under final estimations and will be precisely defined after the co-design of the NBSs and the zones of intervention. The location of the specific interventions related to the co-implementation of the NBSs is in about 20 vacant lots provisioned by the plans as part of the green infrastructure and public spaces in the four residential estates, namely Lev Tolstoy, Nadezhda 2 and 4 and Svoboda. The 2,5 km long axis of the Healthy corridor provides connection between Severen park and park Nadezhda and integrates important available territorial resources related to the major themes of the URBiNAT project – mobility, energy, water and nature.

The pool relies on local geothermal resource to provide healthy environment for children’s physical education, training, and recreational activities. A millennia-long regional cultural tradition of living in contact with mineral water is revived. The ancient city of Serdica once emerged by a mineral spring, which is still in the historic core of Sofia. Public baths with pools have been used in the region for centuries. Swimming has been a compulsory element of school physical education and training in Bulgaria since mid-1970s, yet only few large school complexes had functioning swimming pools by late 1980s. The life-cycle concept developed for the school swimming pool puts an explicit focus on the interaction between authorities, experts, teachers and pupils, and community actors in building the functional and spatial design concept of the pool complex and its integrated management.