With its unusual position "poking" out into the sea, over the centuries the city has been the landing place of great civilisations that have left important evidence of their passage: from the cathedral of San Ciriaco to the I century AD Roman amphitheatre and the Arch of Trajan. The Pinacoteca Civica - which boasts one of the most remarkable collections in Marche, with works by Titian, Sebastiano Del Piombo, Guercino and Crivelli- connserves the Sacra Conversazione, also known as Lotto's Altarpiece of the Halberd. The work was commissioned to commemorate the events that occurred during the tyranny of Cardinal Legato Benedetto Accolti, with each character and object with a specific meaning in a cross-referencing of looks and symbols. Elsewhere in Ancona, the church of San Francesco alle Scale safeguards another work by Lotto, the altarpiece of the Assumption painted in 1550: a Venetian work in its essence marked by a concise and emphatic manner. Another Lotto site is the Loggia dei Mercanti, where an auction of his paintings took place in 1550.