The apex court ordered the halt of all construction and digging in the Margalla Hills.
It also asked the Capital Development Authority to form a committee to conduct a survey on the national park and prepare a report. The report should be submitted to the registrar of the Court within two weeks.
Chief Justice Iftikhar Chaudhry said progress on developmental work is appreciated but preservation of national and environmental heritage should be given importance.
The National Highway Authority had argued the construction of a tunnel would not harm the spirit of the park.
The government had been considering the construction of a tunnel through the Margalla Hills - connecting Islamabad to Haripur - as part of the Pakistan-China trade corridor.
NGOs and environmental organisations claim that going ahead with the tunnel will give rise to environmental and health issues.
Following the controversy which surrounded the project, the Chief Justice took suo motu notice of the issue.
