The Dana Lighthouse standing at the mouth of the Poros channel was built in 1870 by the French Society of Ottoman Lighthouses. It is one of the prettiest stone-built square lighthouses in Greece and a monument of modern maritime history. The lighthouse rises to nine meters and its focal length reaches 32 meters.

The iconic Poros clock tower (roloi) was built in 1927 with a donation by Ioannis H. Papadopoulos, a member of Parliament representing Trizina. His gift included the clock mechanism, which was made in America in 1915.

The Russian Naval Base (Rossikos) was built amphitheatrically along a picturesque bay west of the island’s harbor. After the end of the Russo-Turkish war, Poros’s sheltered harbor served as the Russian fleet’s supply station where the Russian built an infrastructure that included kitchens for baking ship's biscuits and warehouses for storing coal and other supplies.

The cathedral of Agios Georgios marks the center of Poros Town’s upper sector. The oldest surviving written reference to the church is in the 1828 census under Governor Ioannis Kapodistrias, who lived briefly on the island. The church is widely known for its hagiography which is the work of one of the most important modern Greek artists, Konstantinos Parthenis.

The 18th-century Monastery of Zoodohos Pigi, or means life-giving spring, is located about four kilometers from Poros Town on a pine-covered slope and is a unique example of island monastery architecture. Its name derives from the island’s only spring, which is lauded in local tradition for its healing properties.

The Poros Folkloric Museum was lovingly created by the members of the Poros Women’s Cultural Association ‘Poriotissa’ founded in 2003 and is included in the association’s founding charter.

The Temple of Poseidon has been dated to around 520 B.C. The peripteral structure was built in the Doric style, with six columns on its narrow sides and twelve on its long sides. It was one of three large sanctuaries dedicated to the sea-god Poseidon in the Saronic area and formed a triangle with the Temple of Aphaia on the island of Aegina and the Temple of Poseidon at Cape Sounio.

The permanent exhibition “Shells and the Sea” is housed in the ground-floor gallery of the Hatzopouleios Municipal Library.