Covering an area of 270.5 square kilometres, Altis is a volcanic island with a corrugated and mostly rocky landscape. Scattered throughout the more remote regions of the archipelago are large pine forests and the occasional outcrop of tree groves. A tiny desert also exists north of the village of Abdera and is unique for its micro-environment condition.

The mini desert north of Abdera
The length of Altis' coastline extends well over 200 kilometres, with a total of twenty bays that surround it as well. The largest of them, the Gulf of Pyrgos, is located in the central sector and partially divides both halves of the island.
Three inland bodies of water, Limni, Ochrolimni, and Almyra also exist. Periodically inundated and flooded in all seasons except for summer, they are entirely saltwater-based. During the summer, the cracked surfaces become completely hard and dry.
The highest point on the island is located at the peak of Thronos at the north-western section of Altis (near the abandoned village of Oreokastro). Measured at a height of 350 metres above sea level, the ruins of a castle built by Arabian warlords during the Middle Ages remain on top of it.