The outermost village of the Handras-Ziros plateau. It is situated about 35 km distant from Sitia and some 8 km inland from the coast of the Libyan Sea so that even though the village is not right on the coast the inhabitants are fishermen as well as farmers. The village is not mentioned in the Venetian census of 1583, not even under its old name which was "Tso".
The present name comes from the central church which is dedicated to, the Holy Trinity, but the derivation of the original name Tso is uncertain and no basis can be found to support the view that it comes from an old family of that name. Emm. Angelakis writes that the village existed during the years of the Venetian occupation but was destroyed by Turkish pirates in 1471 AD and that the site was rein habited in the 16th or 17th century. P. Faure who has done research on the Venetian archives in Crete says that the name Tso is not found at all in the deeds of the Venetian period.
The hamlets of Dasonari, Leivari, Achladi, Stalos and Amygdali also belong to the community of Agia Triada. Archaeological research in the vicinity of these small settlements resulted in many indications that this area was occupied during ancient times, especially at Stalos where a Minoan settlement and tholos tombs were found, and in the Leivari district where the Alogara cave was used as a dwelling during the Minoan period.
From the book "Sitia", N.Papadakis, Archaeologist,1983