John McLellan complains about people who are "unelected and appointed by the unaccountable" seeking to influence the outcome of planning decisions that affect Edinburgh's World Heritage Site ("Heritage and the zeal for the status quo", The Herald, February 25). Anyone who knows anything about World Heritage (and I know something, having led a four year-long campaign to prevent a multinational company from quarrying in the buffer zone of the New Lanark World Heritage Site), will know that much of what he writes is wrong. Neither James Simpson (the Vice President of ICOMOS-UK), nor "his cronies" (whoever they are) has a "direct line into Unesco". Nor is the role of Unesco or its officials comparable to that of Angela Merkel or the European Union.

The UK's membership of Unesco did not compel the-then Secretary of State for Scotland to put forward Edinburgh's New and Old Towns to be awarded World Heritage Status by Unesco, any more than Nicola Sturgeon or Fiona Hyslop were compelled to support the nomination of the Forth Rail Bridge. For a site to be awarded World Heritage Status, it must fulfil specified criteria that demonstrate its "Outstanding Universal Value". Thereafter, Unesco's World Heritage Committee receives reports on its sites in order to evaluate their "state of conservation". This is not only perfectly reasonable, but it would be negligent not to do so. There is nothing legally that Unesco can do to prevent a planning application that harms a site's Outstanding Universal Value. If Edinburgh Castle were to be demolished and replaced by a Scottish Disneyland then doubtless Unesco would remove the city from its list. But it could do nothing to prevent it.

There is a debate to be had over the effectiveness of World Heritage Status in protecting its sites, and indeed whether it inadvertently devalues other important heritage assets that enjoy lesser designations,

However, in the absence of a single constructive suggestion it is unclear what function Mr McLennan's article was intended to serve, other than perhaps performing the role of a therapeutic whinge.

Professor Mark Stephens,

Mid Lodge,

Bonnington,

Lanark.

It is strange indeed that John McLellan and I should criticise certain individuals, but for very different reasons.

Your columnist vents his spleen on Unesco's Mechtild Rossler whom he superciliously labels "the Angela Merkel of the conservation world". He states that he has no idea if she has ever visited Edinburgh. In fact, she arrived in Edinburgh on November 8, 2008 on an investigative mission with the Viennese architect, Manfred Wehdorn. Given that Dresden had been stripped of its World Heritage status for building a bridge a mile outside its historic centre, it looked distinctly possible that Edinburgh, too, might lose its Unesco designation.

A week later they were reassuring civil servant Peter Marsden of the Department of Culture, Media and Sport in London that there would be no question of Edinburgh losing its World Heritage Status. Not only had they spiked their own guns: they had effectively given the green light to a wave of destructive proposals including a gruesome "copper spiral" hotel beside Robert Adam's Register House which would raise eyebrows on the Las Vegas Strip; the "Mickey Mouse ears" plan to add modern blocks on either side of the A-listed Royal High School (one of the most important Neo-Greek buildings in the world); the wrecking of the south side of St Andrews Square; and the imminent destruction of the last First New Town block between St Andrews Square and Register House. The list could go on.

My view was that this was a dereliction of duty by Unesco, a matter which I raised with the UN Board of Auditors in New York in last year. It would seem to me that Unesco and Professor Rossler are engaged in a damage limitation exercise.

Mr McLellan also aims a low blow at the retired architect James Simpson for the apparent sin of having an affection for Edinburgh's built heritage. I really don't know what his agenda is, or why he dislikes old buildings, but I worry about his lack of balance.

David J Black,

6 St Giles Street,

Edinburgh.