This is a glorious example of Regency architect John Nash's genius. Between 1812 and 1830, under the patronage of George IV (Prince Regent until George III's death in 1820), Nash was the architect for the grand scheme of Regent Street and the sweep of neoclassical houses encircling Regent's Park. The Prince Regent, who lived at Carlton House, had plans to build a country villa at Primrose Hill (to the north of the park), connected by a grand road -- hence Regent Street. Even though it was considered a most extravagant building for its time, Carlton House was demolished after the prince's accession to the throne. Nash's Carlton House Terrace, no less imposing, with white-stucco facades and massive Corinthian columns, was built in its place. It was a smart address and one that Prime Ministers Gladstone (1856) and Palmerston (1857-75) enjoyed. Today Carlton House Terrace houses the Royal College of Pathologists (No. 2), the Royal Society (No. 6, whose members included Isaac Newton and Charles Darwin), the Turf Club (No. 5), and, at No. 12, the Institute of Contemporary Arts, better known as the ICA. Tube: Charing Cross.