Alonissos is the third largest island in the Northern Sporades archipelago. The island is dominated by limestone throughout its whole extent, with upper quaternary lake deposits at the SW part. It is of generally hilly landscape and has a relatively low elevation, reaching about 475 m asl at Kouvouli Mt. Other significant peaks are Geladias (449 m), Xiropefko (400 m), Serafeim (388 m), Galanou Rachi (346 m), Tourkovigla (340 m), Frouros (331 m), Kalovoulos (325 m), Vouno (260 m) and Strovili (255 m), which together with the hills of Skopelos form a perpetual mountain range.
Apart from hills, the geology of the island is also comprised by gorges, steep cliffs ending abruptly into the sea, caves, bays, small capes and lowlands (especially at the SW part). Numerous offshore rocky islets also surround the island, such as Manolas off the northern coast and Kokkinonisi off the southern coast.
 |
| View from the foothills of Vouno towards the northern coast |
 |
| View towards the hills at the central part of the island, including Tourkovigla on the right |
 |
| View from Serafeim hill towards Kouvouli and the plain of Gerakas |
 |
| View from Koumarorahi hill towards Agios Dimitrios and Peristera |
 |
| View from the top of Kalovoulos, Manolas islet can be seen |
 |
| Manolas and the smaller Stavros islet |
