Jakarta Cathedral: connected to Southeast Asia’s largest mosque by an underground “Tunnel of Friendship”

On Jalan Katedral, in the centre of Jakarta, the cathedral of the Assumption of the Blessed Virgin Mary is the seat of the Catholic archdiocese of Jakarta. A first church on the same site, opened on 6 November 1829, collapsed through structural weakness on 9 April 1890. The present building was rebuilt between 1891 and 1901 to a neo-Gothic design by the Dutch Jesuit and architect Antonius Dijkmans, trained under Viollet-le-Duc and Cuypers. After an interruption for want of funds, the work was taken up and completed by the architect Marius J. Hulswit, who simplified the design, replacing some structural elements with cast iron. The consecration took place on 21 April 1901 at the hands of Monsignor Edmundus Sybrandus Luypen. The three towers, two twin spires of sixty metres, called the «Tower of David» and the «Ivory Tower», and a central spire of forty-five metres named «Angelus Dei», rest on steel frames and unreinforced masonry, not up to modern seismic standards. That is why they have been monitored since 2017 with accelerometers and inclinometers, although no concrete risk of collapse is documented. The archdiocese of Jakarta, erected as apostolic prefecture of Batavia on 8 May 1807 according to most sources, and raised to metropolitan archdiocese on 3 January 1961, has been led by Cardinal Ignatius Suharyo Hardjoatmodjo since 2010. According to Indonesian sources he tendered his resignation on reaching the canonical age limit in 2025, but Pope Francis is said to have asked him to stay in office until 2027. Indonesia, the largest Muslim-majority nation in the world, officially recognises six religions within its State ideology Pancasila, Catholicism among them. In 2020-2021 the «Terowongan Silaturahmi» was built, an underground tunnel twenty-eight metres long that links this cathedral directly to the Istiqlal Mosque, the largest in Southeast Asia, standing right opposite. Conceived both as a symbol of interfaith harmony and as a practical solution for sharing car parks on the respective feast days, the tunnel was publicly praised by Pope Francis on 5 September 2024, during his visit to the mosque. The day before, on 4 September 2024, the same pope had visited this cathedral, meeting there about one thousand two hundred Indonesian bishops, priests, religious and catechists. Before him, Paul VI came in December 1970 and John Paul II in October 1989, although for the latter a specific visit inside the cathedral building is not confirmed. On 24 December 2000 this cathedral was among the five churches of Jakarta targeted by a coordinated series of attacks on Christian places of worship across Indonesia, which caused eighteen to nineteen deaths in the country in all.