reading terminal market

International Day of Monuments & Sites

International Day of Monuments and Sites is celebrated annually all over the world on April 18th as a way to honor heritage, diversity, community, and the environment. 

GPA works tirelessly to promote Philadelphia’s staggering 67 National Historic Landmarks by creating an easily accessible map for tourism and heritage interests. GPA has formed a community within the city’s 67 National Historic Landmarks, offering members, city residents, and tourists alike to learn about cultural heritage and all of the hidden gems of our World Heritage City.

A community has taken root within the network of the 67 NHLs, with Global Philadelphia there to organize events, tours, SDG partnerships, and educational opportunities in our Learn Philly Heritage program. IDMS is a day for all of these NHLs to come together and acculturate the Philadelphia community. 

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On 18 April 2023, the world celebrated the International Day for Monuments and Sites with the theme "Heritage Changes".

This annual event, established by ICOMOS in 1982, provides an opportunity for heritage enthusiasts and organisations worldwide to come together and celebrate the importance of cultural heritage.

Participating NHLs from IDMS 2023


Old City / Center City: 

Reading Terminal Market 

The Atheneum  

Hill-Physic House  

The Masonic Temple




Historic Rittenhouse Town

North Philadelphia:

Girard College

Wagner Free Institute

Henry O Tanner Family House

Historic Church of the Advocate

John Coletrane House

Stay tuned for more information about IDMS 2024!

Prepare for 2024 by learning more about the events, webinars, tours, and classes that took place during IDMS 2023?