"Construction on third-party land" written by dr hab. Andrzej Kubas, professor at the Jagiellonian University, in 1969 is a comprehensive monograph concerning the legal institution provided in the Article 231 of the Polish Civil Code. The monograph presents the whole range of different views in the Polish legal doctrine. Having analyzed the wording of the statutory provision, the author presents his own thoughts and ideas. In particular, three questions are raised: how to interpret the concept of good faith, whether Article 231 of the Polish Civil Code may be applied to relations between co-holders, and if so how such situation differs if such co-holders built the building together. Then it attempts to resolve the difficulties concerning the determination of a difference between the value of a new building and the plot of land, persons against whom the claim for purchases should be pursued in various situations and the ways of enforcing the claims under Article 231 of the Polish Civil Code. Finally, there are some examples of changes which can be made by the agreement of the parties. Although written almost 40 years ago, most of the book remains relevant. Not every idea of the author has withstood the test of time, but the book is still a must read for every lawyer who has to deal with the issue of building on a third-party land.