International Day for Monuments and Sites (18 April)

The International Day for Monuments and Sites is celebrated every year on 18 April. It is a date proposed by the International Council on Monuments and Sites (ICOMOS) to draw attention to the diversity of cultural heritage, its vulnerability and the work needed to conserve it. In Portugal, the day takes the form of a national programme of visits, conferences, workshops and special openings, promoted by public institutions, municipalities, museums, universities and associations. The next edition is on 18 April 2027, a Sunday.

Origin: from Hammamet to UNESCO

According to ICOMOS, the idea was born at a symposium of ICOMOS Tunisia and a meeting of its bureau in Hammamet, on 18 April 1982. It was then proposed to create an annual day to celebrate heritage on a worldwide scale. In its current presentation, ICOMOS contrasts this global reach with regional celebrations, such as the European Heritage Days in September. The ICOMOS council approved the project and gave practical guidance to its network for organising the commemorations.

The date gained wider prominence when the UNESCO General Conference, at its 22nd session, in 1983, adopted the concept. In 2001, the then president of ICOMOS, Michael Petzet, and the organisation’s council proposed that 18 April also serve to draw attention to a type of heritage particularly under threat. This is why each edition now has a theme.

The English name is International Day for Monuments and Sites. The date is not limited to properties inscribed on the World Heritage List: the themes and activities cover monuments, archaeological sites and living heritage of all kinds.

A different theme each year

The theme is chosen and announced by ICOMOS International for each edition. National committees, such as ICOMOS Portugal, and local partners adapt it to their programmes.

Two recent examples, as presented in Portugal:

• 2024: “Catastrophes and conflicts in the light of the Venice Charter”, the year in which that 1964 conservation charter turned 60.
• 2026: “Living heritage: emergency response in contexts of conflicts and disasters”. In ICOMOS’s English version, the theme is Emergency Response for Living Heritage in contexts of Conflicts and Disasters.

The theme for 2027 had not yet been published when consulted on 5 November 2026. It is usually released by ICOMOS before each edition, so consult the ICOMOS website and the Património Cultural page.

How it is marked in Portugal

The Património Cultural, I.P. presents itself as the body responsible for national coordination of the day since 2024, in collaboration with ICOMOS Portugal. The model is open. The institute invites public and private entities to register their activities, in person or online, on a dissemination platform. It also provides a graphic kit so that everyone uses the same identity.

In 2026, the institute’s page announced activities from 11 to 19 April. The theme carried special weight after the extreme weather events of the previous winter. According to Lusa, the programme brought together more than two hundred initiatives across the country: guided visits, exhibitions, workshops, concerts, conferences and film screenings. One of the institute’s proposals, “Living Heritage – Enter the Worksite”, opened the backstage of ongoing conservation works. It included the Palácio Nacional de Mafra, in the Convento de Mafra, the Mosteiro de Tibães, the Mosteiro da Batalha and the Abrigo do Lagar Velho, in Leiria. These were free visits, but with mandatory registration.

The same day mobilises other entities with their own programmes, such as municipalities, Misericórdias, universities and museums under other authorities. The ICOMOS international page for 2026 referred to the Portuguese portal and also noted a seminar at the Universidade Portucalense on heritage risks and vulnerabilities, on 28 April. Not all activities are free, and many require prior registration.

Free entry on 18 April?

There is no fixed rule. Free admission on that day depends on decisions taken each year by each managing entity. In 2024, Dispatch No. 22/GCD/2024, of 4 April, signed by the president of Património Cultural, I.P., determined free entry on 18 April to all monuments and sites under the responsibility of Património Cultural, I.P. That dispatch did not cover the museums, monuments and palaces managed by Museus e Monumentos de Portugal, E.P.E., nor the sites of other entities.

When consulted on 5 November 2026, an equivalent decision for 2026 could not be confirmed. For residents in Portugal, there is an annual scheme of free admission to Museus e Monumentos de Portugal facilities, independent of this date. It is explained in free entry to national museums and monuments.

How to find the programme

1. From the beginning of spring, consult the page for the International Day for Monuments and Sites on the Património Cultural, I.P. website.
2. Use the portal eventos.patrimoniocultural.gov.pt. It offers a map, a list and filters, including one for free activities, and also gathers the programmes of the European Heritage Days and the International Day for Intangible Cultural Heritage.
3. For the international dimension and the year’s theme, see the ICOMOS agenda.
4. Before setting out, confirm the opening hours, entry conditions and whether registration is required on the monument’s or organiser’s page.

If you represent an entity and wish to take part, note that in 2026 Património Cultural, I.P. received activity registrations on this same platform, before the date. Check the registration calendar of each edition.

Why it matters

18 April works as a common calendar for the heritage community. It brings the technical work of international conventions and conservation charters together with a programme open to the public. Recent themes, on conflicts, catastrophes and emergency responses, connect directly to the issues addressed in heritage at risk in Portugal. In September, the European Heritage Days offer a second annual occasion in a similar format.