This paper aims to present the work in progress our research team has been carrying out on designing a conceptual 3D model of the main historical monuments of Crete throughout time. We are working on creating an online platform that would be open to the public and would aim to promote the cultural heritage of Crete, through a simple, user-friendly, intuitive environment. We have just started implementing the Conceptual Modeling Language (ConML) as a tool to handle and visualize the large amounts of information that the long list of monuments entails.

Crete is the largest island of Greece, located to the south, famous for its rich cultural history, which dates back to the Middle Paleolithic age, 128,000 BC. Crete was the center of the Minoan civilization (2,700-1,420 BC), the first civilization in Europe. Since then, a large number of monuments has been documented throughout the different historical periods, the most important of which are the following seven (7):

1. Minoan                       
2. Hellenistic
3. Roman
4. Byzantine
5. Venetian
6. Ottoman
7. Modern

Our prime challenge has been how to manage such a large amount of information over the internet, in a transparent, light and simple way for the end user, in addition to offering the ability to compare data over time, during the historical periods. In order to achieve this we have been using the notion of Conceptual Modeling. The idea is simple: instead of having all information to its full extend available up front,  we break it into nodes, levels of abstraction, called “Levels of Detail”, providing the minimum information needed at each given time. Information is stored on each object, each monument, along with its different Levels of Detail. The Levels of Detail that we are using in this platform are the following five (5):

1. Prefectures
2. Cultural provinces
3. Settlements - Towns
4. Building complexes
5. Buildings - Monuments

The platform is comprised of the main, central space, where the 3D models are presented, and two scrollable sidebars, one horizontal and one vertical. The horizontal one controls time, and allows the user to switch between the seven historical periods and the vertical one controls the level of detail, allowing the user to switch between more or less abstract modes. At the same time, the user has the ability to navigate in real time in the main space around the models, using pan, zoom in/out, rotate, etc. Only when the user reaches the fifth Level of Detail, that of a single monument, he/she has access to all the available related information, such as photographs, videos, maps, drawings, text, links, etc. Use of keywords allows a cross-reference function independent of the 3D models.

The primary contribution of the proposed platform, we believe, is the ability to capture time in a comparative format. Some of the topics we are working on are:

- subjectivity due to abstraction

- use of multiple semantic links

- interoperability / expansion

- the world of BIM (Building Information Modeling). What can we learn from it?