Churches • Holy Trinity church () (1892) at Ammos. • Virgin Mary church () near Stavros district. • Saint George church() (about 1864) at Chorio. • Agia Paraskevi church () (and the old stone mill) at Damaskatika.
Other buildings •
School of Othonoi () (1912) at Ammos. • Ruins of the Venetian fortress at the northeast end of Kastri cape hilltop at an altitude of 100 m. •
Lighthouse of Othonoi () (built in 1872).
Monuments •
Cross monument at Stavros, for the massacre of the inhabitants of Othonoi by the Ottoman fleet under Hayreddin Barbarossa in 1537. • Monument to seafarers of Othonoi island, at Ammos. • Monument to submarine PROTEUS, at Ammos.
Nature • Aspri Ammos beach () which is accessible only by boat to the west of the island. • Cave of Calypso (), near of Aspri ammos beach. • Mount
Imerovigli () and the highest peak of the island with height of • Kamara () near Ammos. • Iliovasilema (sunset) at Chorio.
Beaches Most beaches on the island are accessible by boat, including Ammos, Molos, Kamini, Kanoula, Kontoskes, Rogi, Fyki, Xilosermi, and Aspri Ammos. It is a well-known island for underwater photography because of the peculiar
geomorphology of the seabed and the many caves. Other points of interest are the Moshopontikas, Xylosermi, Fyki bay (where there is the sunken wreck of
Sarah ship). Othonoi was frequently visited by the French naturalist
Jacques Cousteau and his exploratory vessel
Calypso.
Trails The traditional trail was created and used by the first inhabitants and was subsequently reopened by the municipality and private initiatives. Locals and visitors can use the trail to reach almost every neighborhood and part of the island on foot, as well as Mount
Imerovigli (Merovigli), and the highest peak of the island, with a height of over , with views of the other
Diapontia Islands,
Ionian Sea and
Adriatic Sea.
Others •
Port of Ammos () is the most populous district with small guesthouses, restaurants, rent-a-bike store, cafes, police station, a community clinic with ambulance and port authority. == Nature ==