Sean Penn (search) is trading screenplays for a reporter's notebook yet again.

The Oscar-winning actor traveled to Tehran, Iran, in June. The San Francisco Chronicle (search), which has published previous accounts of his travels, is running a five-part series on his experiences this week.

In the first installment, Penn wrote about the difficulties of obtaining a visa to travel to Iran, how women are instructed to cover their faces before landing in the country and some tense moments when he was fingerprinted entering Iran.

The actor compared the bustle of Tehran to Baghdad or Mexico City, saying the city was filled with "Jousting, yelling, horn honking and warm thickly polluted air, mud-splattered motorcycles, winding through human traffic at death-bound speeds."

Penn landed in Tehran the week before the Iranian elections.

Given a press credential by Chronicle Executive Editor Phil Bronstein, Penn visited Iraq in late November 2003, shortly before Saddam Hussein was captured.