This review paper focuses on structural properties, fabrication methods, and advantages of castellated beams, especially the modern application in construction of beams that came into existence in the mid-20th century. Castellated beams, as normally defined by their web openings, have gained popularity over the years with this additional advantage of increasing the depth of structural construction without adding material weight, thus having greater loads and saving costs. Several forms of castellated beams exist, such as hexagonal, cellular (circular), octagonal, and rectangular opening types, every one offering its special advantage in a particular type of structural application. A part from the difference in geometry, the basis of this study on castellated beams also centres on the applicability of finite element analysis in the determination of failure modes and more accurate designs, particular to lateral-torsional buckling and web post-buckling. Following are the key findings. Low-grade steel, having thicker flanges, has shown better economic efficiency. The paper discusses the problems of lateral-torsional buckling, web post buckling, ruptures and Vierendeel mechanism, in the welded joints due to stress near around openings. It also highlights the flexibility of the castellated beam, which allows for the service integration of elements such as electrical conduits and HVAC systems, that enhance architectural flexibility and environmentally sustainable designs also this paper highlights potential gaps in research mainly related to lateral-distortional buckling versus varying sizes of an opening, by an extensive numerical and experimental study based on FEA simulations by ABAQUS. Future studies are recommended to optimize the design of castellated beams by looking into the effects of opening shape and size on stability and innovative stiffening techniques for improved performance under load-carrying application. This research contributes toward further advancing the castellated beams to better develop guidelines for design with economic and environmental benefits in structural engineering.