The physical makeup of Re:Zero's world is that of a flat world not dissimilar to a diorama instead of a globe. The Great Waterfall marks its end, and beyond it lies supposedly an abyss. Like Earth it has a day and night cycle with its own sun and moon. However it follows the Ptolemaic model in terms of rotation and orientation. Also like Earth it runs on a 24 hour period and has four major seasonal climate patterns. Its months consists of at least 25 days.
It is unknown how many landmasses there currently are or were before the "Great Calamity" brought on by the Witch of Envy destroyed half of the world. The main story however takes place in a large continent that houses 4 great major powers: Gusteko to the barren north,Vollachia to the fertile south, Kararagi towards the west and finally Lugnica at the far eastern edge of continent which borders the Great Waterfall. Beyond them there are several smaller vassal and independent states that surround and sit in between them.
Despite the presence of bodies of water, the world has no actual ocean. The largest accessible source of water apart from the Great Waterfall comes from large lakes, and then smaller rivers and streams. The lakes themselves are quite salty and provide much of the world's salt or equivalent.