The most famous and disputed of the architect's work is his Royal National Theatre on London's South Bank. Prince Charles compared it to a nuclear power station but it was popular with other traditionalists, with John Betjeman writing Lasdun a letter in praise of its design. Lasdun (or his firm Lasdun, Softley and Partners) designed the neighbouring IBM headquarters (finished 1985) as a continuity with the theatre. His European Investment Bank in Luxembourg was similar. The last work produced by the firm in London was an office block called Milton Gate near the Barbican Estate, which in its use of green-tinted glazing represented a departure from his familiar bare concrete style.