Legal stuff goes here
https://zakon.hr/z/450/Zakon-o-nadzoru-dr%C5%BEavne-granice
(From Gregor)
Then I went to look up this law: https://www.zakon.hr/z/294/Zakon-o-%C5%A1umama
And now here is translation (google) of this article 40.
Creation and adoption of spatial plans
Article 40 (Official Gazette 115/18)
(1) Only forest infrastructure, hunting management and hunting technical facilities, buildings for the purposes of defense and surveillance of the state border, monuments marking the places of mass graves of war victims and places of suffering, and buildings planned by spatial plans can be built in the forest and on forest land.
(2) Spatial plans can be used to plan the construction of buildings in the forest and on forest land only if, due to technical and economic conditions, it is not possible to plan outside the forest and forest land.
(3) In stands I. and II. age class, stands that are in the stage of harvesting, forest seed facilities and forests intended for scientific research and teaching, the construction of camps, golf courses and other sports and recreational areas cannot be planned with spatial plans.
(4) At the invitation of the holder of the preparation, the public forest owner makes requests in the process of preparation of spatial plans.
(5) In the process of adopting the State Spatial Development Plan, County Spatial Plan or City of Zagreb Spatial Plan, Spatial Plans of Special Features, Spatial Planning Plan of the City or Municipality, which relate to forests and forest lands, the Ministry issues an opinion.
(6) The public forest owner, institution, legal entity and public institution, within the framework of their jurisdiction, shall submit a statement to the Ministry on spatial plans for the purposes of giving an opinion from paragraph 5 of this article.
(7) For the purpose of issuing a location permit and drawing up a master project when a location permit is not issued in accordance with a special regulation, special conditions for the construction of buildings from paragraph 1 of this article and the construction of facilities within a zone of up to 50 m from the edge of the forest for forests and forest lands in owned by the Republic of Croatia is determined by the public forest owner, Institution or Legal Person, and for forests by private forest owners, the Ministry.
(8) Forest owners are not required to undertake special protection measures, nor can they be held responsible for any damage to buildings built within a zone of up to 50 m from the edge of the forest.