The John Muir Trust (JMT) has backed a campaign aiming to maintain public access to Cape Wrath.
At present, the peninsula is owned by the Northern Lighthouse Board, but the Ministry of Defence has declared an interest in buying the 58-acre property.
This would mean those who like to go walking
there would no longer be able to do so, with a letter released this week written by defence personnel minister Mark Francois stating that such a purchase would mean no access for "reason of health and safety".
Durness Development Group is among the opponents, arguing this would damage local tourism and they are backed by the JMT.
Chairman of the Trust John Hutchison said: "It is unthinkable that Cape Wrath should be turned into a military exclusion zone, from which the people of Scotland and overseas visitors are locked out."
Cape Wrath marks the northern end of the 470-mile Scottish National Trail, which was formally opened by Scotland's first minister Alex Salmond in October.
It was devised by mountaineer and outdoors writer Cameron McNeish.