Telok Ayer Street was once part of Singapore's shoreline, and migrants who arrived by sea built their places of worship nearby.
The area displays remarkable religious diversity even now, Prime Minister Lee Hsien Loong said in a Facebook post yesterday.
He went on a walking tour of five places of worship along the street on Wednesday, and met leaders of the church, temples, mosque and shrine that have been there for more than a century.
Race, language and religion are faultlines that have torn many societies apart, Mr Lee noted in his post, which came on the eve of Racial Harmony Day.
"Singapore is a rare and precious example of a multi-racial, multi-lingual and multi-religious society where people live harmoniously together," he wrote.
"This is not by chance. The government and the different communities worked hard together to make this happen."
The Harmony in Diversity Gallery, which houses exhibits and interactive features that highlight the common thread among the different religions, is one such collaboration, said Mr Lee.
He stopped at the gallery in Maxwell Road, where he met members of the Inter-Religious Organisation (IRO), and wrote: "Long may we live peacefully and harmoniously in multi-racial and multi-religious Singapore."
He also posted a photo of one of its exhibits, a trick-eye mural of a kopitiam, which he said was an important common space for Singaporeans of all races and religions.
Mr Lee's first stop on Wednesday was the Telok Ayer Chinese Methodist Church, where services are still conducted in Hokkien. It was set up for immigrants from China's Fujian province, and during the Japanese Occupation provided them refuge.
Mr Lee then went to the Al-Abrar Mosque, which served the Chulias - Tamil Muslims who were among Singapore's earliest immigrants.
He next visited the Thian Hock Keng Temple, one of the country's oldest Hokkien temples, then moved next door to Taoist temple Singapore Yu Huang Gong.
The Taoist temple was previously the site of Keng Teck Whay Association, which was started in 1831 by 36 Hokkien Peranakan merchants from Melaka. It still houses the Peranakan ancestral hall and clan complex.
Mr Lee ended his tour at the Nagore Dargah Indian Muslim Heritage Centre. Originally a shrine built in honour of holy man Shahul Hamid from India, the centre now has an exhibition that pays tribute to the contributions of Indian Muslim pioneers here.
Mr Lee wrote: "My thanks to the Ministry of Home Affairs, the Inter-Religious Organisation and members of the different faith communities in Singapore for helping to build a harmonious and peaceful Singapore."