, the Greek National Aggregator for Digital Cultural Content

About is the Greek Aggregator for Cultural Content and National Provider for Europeana.

A wide variety of digital resources is accessible via archaeological items, historical documents and manuscripts, items of material culture, works of art, cartographic material, books and intangible heritage resources. The digital files are primarily photographs and other images, pdfs, 3D models and audiovisual material.

So far, has amassed more than 430,000 items from 67 collections contributed by 53 institutions which include museums, archives, ephorates of antiquities, municipalities and cultural foundations. has contributed 54 collections (more than 562,119 items) to Europeana.

Digital content is licensed by the owning institutions with open Creative Commons or other licenses, in accordance with any restrictions imposed by copyright and protection of cultural heritage legislation.

If you are an organization with cultural content and wish to be part of this dynamic network represented in and Europeana you can find out more here and declare your interest by submitting a form.

If you do not have an institutional repository which we can draw content from into, you can use EKT’s Repository Service. It is a full SaaS (Software As A Service) service which allows you to develop your own repository, according to your needs and organizational structure and carrying your own brand and communication preferences. Your content will be aggregated into and then on to Europeana, ensuring its widest possible reach and dissemination. Find out more about EKT’s Repository Service here.

Development has been initially developed by EKT as part of an aggregation and preservation framework established and implemented in collaboration with the "Digital Convergence" OP (National Strategic Reference Framework).

The objective was to ensure the sustainability and reusability of content produced by publicly funded digitization projects, to provide central access to digital cultural resources and to integrate them to Europeana. EKT was assigned with the important role of National Aggregator and Preservation Infrastructure for projects funded by Cultural Heritage Digitisation related Calls of the OP. The role involves setting the quality and interoperability specifications for publicly funded projects (metadata, digital files and systems), validating and certifying systems and content, publishing the produced content in, depositing it in a preservation platform, and, eventually, delivering it to Europeana.

The first phase in development of was supported by the project "Platform for provision of services for deposit, management and dissemination of Open Public Data and Digital Content" of the Operational Programme "Digital Convergence" (NSFR), co-funded by Greece and the European Union. The first version went into production in 2015.

Since January 2019, the National Documentation Centre is the national accredited aggregator for Greek cultural data to Europeana, via its service EKT participated to the European CEF-funded “Europeana Common Culture” project which ended in December 2020, through which it delivered more than 300.000 objects to Europeana. It also improved the metadata tiers through semantic enrichment for all the data it delivers to Europeana (more than 500.000 objects) thus significantly enhancing the findability of Greek content online. Overall, the project aimed at strengthening the role of national cultural data aggregators through the interchange of know-how and the streamlining of policies and technologies used by them.

Since 2020, the development of is being supported by the project "National Information System of Research and Technology: Infrastructure of Aggregation, Documentation and Dissemination of Digital Content that promotes interoperability, long-term preservation and open access" NSRF |

Discover content offers a contemporary content discovery experience.

Users can search by entering a word or phrase and by applying combination filters: content type, subject, chronology, historical period, license, institution and collection. There are also interactive features to support exploration of content: tag clouds for types and subjects, a timeline and dedicated pages for navigating by type, subject, historical period, institution and collection. Users can also filter search results with facet queries by choosing from a wide range of filter fields, including homogenized and original content type, homogenized and original content subject, time period, homogenized chronological period, language, license, institution and collection.

Users can enter complex questions such as "middle era Byzantine coins", "classical sculptures" or "paintings of post-war era". Users can choose a type, for example "vase," and then, using the result filters, navigate through historical periods or chronological periods, exploring in this way the evolution of pottery in the history of Greek culture. Go to help for more advice for search and navigation features in

Another way for discovering content is through Thematic Exhibitions. Thematic exhibitions are smaller or larger sets of items that tell a story, grouped thematically and conceptually. The thematic exhibitions highlight the range and variety of history, arts, archaeology, social and science topics that you can explore at has two additional ways of publishing data. The Web API allows third-party applications to search for and display data aggregated here. Linked Data is a publishing approach which allows data integration and use.

Infrastructure & Services is the public portal of the Aggregator platform, a digital content aggregation system. It is a component of a broader infrastructure comprised of four other systems: Harvester, a digital content harvesting system, Validator, a system for validating content against interoperability and quality specifications,, a system for semantic enrichment, and Preservator, a system used for the secured and long-term preservation of digital resources. The infrastructure along with the individual systems were designed and implemented by EKT. These were the basis for developing a series of high value services to the

Content and Interoperability Validation Service

EKT validates and confirms the extent to which individual repositories comply with content quality and interoperability standards

The specifications developed for this infrastructure relate to metadata standards, digitization and interoperability protocols and are the sum of years of experience, international best practices and established standards. The specifications take into account documentation and digitization requirements by category of material (eg printed matter, photographs, maps, works of art, etc.) as well as requirements for the ingestion by Europeana and other recognized international organizations. You can find the latest edition (October 2020) of the Interoperability and content quality specifications for publishing on-line digital cultural content here.

Preservation Service

The Preservator system keeps back-up copies of the aggregated content (metadata and digital objects) in the trustworthy Cloud-based infrastructure of EKT, to ensure its long-term secure storage and accessibility, protecting the born-digital and digitised resources from physical and technical calamities. EKT has recently loosely coupled the Preservator system with in order to guarantee that the digital resources will still be accessible via and Europeana even when individual repositories face technical issues.

Semantic enrichment

EKT enriches, homogenizes and organises the aggregated content of by developing vocabularies and advanced data mining and semantic enrichment tools.

EKT enriches the metadata using a Vocabulary of Item Types that we created and published in The vocabulary is hierarchical and bilingual and is linked to the Getty Art & Architecture Thesaurus (AAT) and the semantic thesaurus DBpedia of Wikipedia. Metadata records were enriched with a separate field "EKT type" that holds references to the vocabulary. Depending on the collection, the enrichment is based on original values of “dc:type” and, for special cases, of “dc:subject” or “dc:title”.

EKT also enriches the aggregated metadata with homogenized (normalized) chronologies and with historical periods using a hierarchical bilingual vocabulary of Greek Historical Periods. The vocabulary is linked to the semantic thesaurus DBpedia of Wikipedia. Metadata records are enriched with two separated fields, "EKT chronology" and "EKT historical period". Depending on whether the original temporal documentation is based on period labels or chronologies, we adopted two fundamentally different enrichment strategies, historical period-driven enrichment and chronology-driven enrichment, respectively. In the historical period-driven enrichment, items originally described with period labels are mapped to vocabulary terms and they are also enriched with the respective year ranges. In the chronology-driven enrichment, chronological values are being homogenized into years or year ranges and then, based on the results, the items are enhanced with the corresponding terms from the historical periods vocabulary. The enrichment is based on the original values of a temporal field (“dc:date”, “dc:created” or “dcterms:temporal”, depending on the collection) and in special cases taking into account keywords in descriptive field values, such as of “dc:description” and “dc:title”.

Items are also enriched with a new field "EKT Subject" that includes references to terms of a bilingual and hierarchical vocabulary of thematic categories created by the EKT that constitutes the Greek version of the UNESCO Treasurus and of a bilingual vocabulary of thematic tags that is complementary to the UNESCO Thesaurus and covers more specific topics. You can see the two interlinked vocabularies as a common hierarchy here. The enrichment is based on the original values of the "subject" metadata field.

The semantic enrichment allowed us to publish the content as Linked Data and to develop advanced multilingual search and browsing features, including hierarchical navigation on types and historical periods, searching and faceting on types, time spans and historical periods, a tag cloud of types and an interactive timeline.

EKT & Europeana

EKT is the accredited National Aggregator for Europeana for Greece. It has developed workflows and procedures for integrating its content into the European Digital Library. Presence in Europeana ensures even greater visibility for the participating institutions. So far, has contributed over 562,119 items from 54 collections/owning institutions to Europeana.

Europeana is a Foundation based on the Netherlands, run by a Board of Directors representing bodies and associations of GLAMs from all over Europe. Since 2008, Europeana developed its portal and now hosts over 50 million digital cultural resources. Europeana has made a significant contribution to the development of a common European consciousness, not only for museums, libraries and archives, but also for citizens and innovation communities. It spearheaded the creation of networks of content collaboration and re-use. At the same time, it highlighted the value of coexistence of heterogeneous digital cultural content and the possibilities of multiple narratives for objects and testimonies of our shared heritage.

For culture, Europeana has been a catalyst, sharing good practices and know-how about content aggregation, as well as participating in pan-European multi-partner projects with a focus on fashion, music, photography and shared European heritage. Its licensing policy, supported by the Open Access movement and the use of Creative Commons licenses, have contributed both to the circulation of knowledge and to the protection of copyright. Organizations with tangible and intangible heritage collections what wish to join and Europeana and participate in a dynamic national and international network of cultural institutions, consisting of museums, archives, archives, universities, associations and cultural organizations, can declare their interest here.