The Prince of Wales has warned that London's new high-rise buildings are threatening to "vandalise" the city's heritage sites.
A view of St Paul's surrounded by skyscrapers and cranes
Speaking at a conference at St James's Palace, Prince Charles said new skyscrapers would leave London with a "pockmarked skyline".
He urged builders to ensure the city retained its "timeless character".
In 2006, the United Nation's cultural wing said the Tower of London was becoming overshadowed by skyscrapers.
Unesco had said the 900-year-old building's historical value was being threatened and that the landmark was on the verge of being placed on its Heritage in Danger list.
The Prince was addressing the New Buildings in Old Places conference, organised by the Prince's Foundation for the Built Environment and the Prince's Regeneration Trust.
He said: "For some unaccountable reason we seem to be determined to vandalise these few remaining sites which retain the kind of human scale and timeless character that so attract people to them and which increase in value as time goes by.
"Thus, in chasing the corporate tenant or the buy-to-let investor, we may not only be destroying our heritage, but killing the goose that lays the golden egg".
Prince Charles gave the example of Berlin, the German capital, where the government has imposed height restrictions on new construction.
He called for an alternative to the "free-for-all" attitude that was leading to a "rash" of new construction that would leave the city with a "pockmarked skyline".