A Pro-revolutionary, traditional building, property of Admiral of Psara Nikolis Apostolis. It was built in 1810 from ashlar porous stone in isodomic masonry. The exterior stonework of Western, Southern and Northern side is constituted by lines of stones of yellowish colour (ochre) and grey, while the Eastern side from the sea is plinth-built. The lintel of the recesses , the candles and the eave,are also made from also from ashlar porous stone.
From the asymmetry of frames it appears that it is building of Folk Architecture. Its uniqueness lies in the combination of different architectural elements. In first impression, the elements of Medieval European architecture are dominant that remind us the giant buildings of Rhodes (as big stones for the layout of stonework, candles, stone sculptures). The small high-arched windows of the floor constitute elements of the Eastern Folklore Art. Also the arched lintel are from the Folklore construction of Central Greece. The aprons of windows that are appeared supported in small form stone corbels are characteristic. In reddishness of the main entrance, in the Southern side the words "Oikos Istioforon" (House of Sailboats) had been engraved, while the existing letters in the main entrance of the Western side have been destroyed.
Within the pro-revolutionary years from year 1810 up to the destruction of Psara by the Turks on 22 June 1824, the building was used as a Naval Chamber by the citizens of Psara. From 1824 and during the turkish occupation where Psara were liberated on 21 October 1912 the Turks used it as a command post (Konaki). After the liberation of Psara in year 1912 up to 1928 it became the first Elementary school (is used between citizens of Psara the building to be called “old school”). Today it belongs to the Municipality and moves are made to be renovated in order to accomodate the Museum of Psara.