Of the buildings dating from the period of Venetian rule, very few have survived. A considerable number were lost to repeated seismic destruction, successive renovations, and the extensive alterations undertaken during the construction of the great 16th-century fortifications. The transformation of the Venetian urban fabric began as early as the Ottoman conquest in 1669. Additions and repairs responding to new defensive, administrative, religious and residential needs, further earthquake damage, and the great fire of 25 August 1898 meant that only a small portion of the Venetian city endured into the early 20th century.
Its final undoing, however, occurred in the decades that followed. Unregulated urban expansion, interventions in the historic fabric to open new thoroughfares and create public spaces, rapid rebuilding, and the difficulty of recognising the monumental value of structures long associated in popular memory with foreign rule, all led to the destruction of a significant part of what remained.

Despite relentless bombardment during the twenty-year siege, the fortifications of Candia survived into modern times largely intact. From the early 20th century, however, they came to be regarded as an obstacle to the planned development of the modern city. The need to allow vehicular access to areas beyond the walls resulted in demolitions near the gates of Pantokrator (Chanioporta), St Andrew (Sofoklis Venizelos Avenue), and Jesus (Kainouria Porta), at the semi-bastion of St Francis (Ikarou Avenue), in the curtain wall between the bastions of Martinengo and Bethlehem (the so-called Kommeno Bedeni), and along the seafront (Duke de Beaufort Avenue).
The town plan of 1936 — fortunately only partially implemented — would have radically altered the surviving medieval layout, erasing the historic centre and diminishing its monuments. In accordance with this plan, the earthen ramparts of the walls were cut back in several places, embankments were created for new avenues, and open areas adjoining the fortifications were converted into building plots, depriving the monument of vital space. The moat before the Vitturi Bastion was filled in to create Georgiadis Park and part of Demokratias Avenue.

In the early 1930s, extensive interventions in the harbour zone, undertaken to form a coastal boulevard and a new pier, led to the destruction of most of the arsenals and their gate, as well as the so-called “Little Koules” at the end of the southern mole. Gradually, open spaces along the level sections of the walls and bastions were appropriated or sold off, and neighbourhoods developed on the sites of the smaller outworks, which were ultimately declassified. Only the large fort of St Demetrios survived in part; upon it grew the district of Analipsis and the Kapetanakeion Secondary School. Within the moat between the bastions of Bethlehem and Pantokrator, the National Stadium was installed. Football facilities were laid out on the Martinengo Bastion, while tennis courts occupied the bastion and moat of Sabbionara.

Ecclesiastical monuments met with a similar fate. Despite efforts to safeguard them through designation as protected monuments by Royal Decree in 1947, many were demolished in the decades that followed. Some survive only as parts embedded within later constructions; others, having been converted into Ottoman mosques, were subsequently granted to private individuals and subjected to incompatible uses or left in a ruinous state. Of the Venetian churches of Candia — whether Catholic or Orthodox — only a handful remain, and fewer still continue in liturgical use.