The last time I stayed at the Laleh Hotel, the doormat was imprinted with a US flag and a banner saying "Death to America" hung in the dining room. One of the first acts of the Islamic revolutionaries who overthrew the Shah in 1979 was to pour the contents of the hotel's bar - it was part of the Intercontinental chain then - down the swimming pool drain. Years into the revolution, its carpets were ragged, the bedspreads full of holes and the bathroom cockroach-infested.
Now the international press corps flocking to Tehran to cover next week's Islamic summit is to be lodged at the Laleh of revolutionary fame.
But it's not quite the hotel it was. Its refurbishment was to have been completed three weeks ago. We had quite a shock when we dropped in yesterday morning to see how work was progressing.
The hotel's grey facade has been painted bright white. The interior is marble, polished brass and huge crystal chandeliers. In the lobby, where desks used to tread on the Stars and Stripes, workmen unrolled a magnificent Tabriz carpet.
Instead of "Death to America", posters now carry the slogan "Islamic Summit: the pleasant hymn of unity".
The conference will provide President Mohamed Khatami, who took office scarcely two months ago, with a unique opportunity to show off the new Iran he is leading. The Laleh's transformation, and the feverish last-minute building of a stone and glass conference palace on the hillside of north Tehran, are symbols of Iranian pride as the civilised face which Tehran wants to show delegations from 55 Muslim countries.
Neither the Palestinian groups, Hamas and Islamic Jihad, nor the Lebanese Hizbullah, all recipients of Iranian largess, have been invited to the summit, not even with observer status.
Just six years ago, Tehran hosted the international conference for support of the Intifada. Because of the presence of extremist groups, which Iran considers as resistance to Israeli occupation, the western media quickly dubbed it a "terrorist conference".
With guests like the Saudi Crown Prince, the King of Morocco, the Egyptian Foreign Minister, and probably Mr Yasser Arafat and King Hussein of Jordan, next week's summit will epitomise respectability.
Tehran is still an exasperating, exhausting city. It is difficult to get used to the 1,000-metre altitude and the dun-coloured lid of smog that suffocates the city.
Seeking accreditation for the summit, we were buffeted between the smart, clean offices of President Khatami's new Iran, staffed by solicitous English-speaking university graduates, and the old Iran of surly policemen and grouchy, unshaven civil servants in baggy suits, sitting at desks covered with sticky paper.
At the Ministry of Culture and Islamic Guidance, irreverently referred to by correspondents as the Ministry of Truth, women workers have shed their navy blue and black regulation hijab (Islamic covering) for equally modest but more cheerful flowered scarves and brightly-coloured raincoat-like roupoushes.
Mr Khatami's Iran feels like a winged creature struggling to emerge from a chrysalis.