Portuguese copyright law allows the use of works permanently installed at public locations. The law explicitly mentions buildings and sculptures as examples of such works (§75(2)q). "Use" includes taking a photograph of such a work and publishing it (§68). However, according to the Berne three-step test, the allowed uses must not conflict with a normal exploitation of the work, nor unreasonably prejudice the legitimate interests of the rights holder (§75(4)).
It is also required to identify name of the author, with no exceptions ("wherever possible", as per §76(a)).